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  • Authors’ response: associations of obesity and circulating insulin and glucose with breast cancer risk
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-02-13
    Shu X, Wu L, Khankari N, et al.

    We thank Tan and colleagues for their careful reading of our manuscript.1 As suggested, we performed two separate analyses for fasting insulin using betas from genome-wide association studies (GWAS) of fasting insulin, either with or without the adjustment of body mass index (BMI). Both analyses yielded consistent results for the association between genetically predicted fasting insulin and breast cancer risk, similar to our original results (Table 1).

    更新日期:2019-02-14
  • Assessing the role of women’s autonomy and acceptability of intimate-partner violence in maternal health-care utilization in 63 low- and middle-income countries
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-02-07
    Sripad P, Warren C, Hindin M, et al.

    Background Our study investigates the associations between women’s autonomy and attitudes toward the acceptability of intimate-partner violence against women (IPVAW) and maternal health-care utilization outcomes. Methods We combine data from 113 Demographic and Health Surveys conducted between 2003 and 2016, which give us a pooled sample of 765 169 mothers and 777 352 births from 63 countries. We generate composite scores of women’s autonomy (six-point scale with reference: no contribution) and acceptability of IPVAW (five-point scale with reference: no acceptance) and assess the associations between these measures and women’s use of antenatal care services and facility delivery in pooled and unique country samples. Results A change in a woman’s autonomy score from ‘no contribution to any decision-making domain’ (a composite autonomy score of 0) to ‘contribution to all decision-making domains’ (a score of 6) is associated with a 31.2% increase in her odds of delivering in a facility and a 42.4% increase in her odds of receiving at least eight antenatal care visits over the course of her pregnancy. In contrast, a change in a woman’s attitude towards acceptability of IPVAW from ‘IPVAW is not acceptable under any scenario’ (a score of 0) to ‘IPVAW is acceptable in all scenarios’ (a score of 5) is associated with an 8.9% decrease in her odds of delivering in a facility and a 20.3% decrease in her odds of receiving eight antenatal care visits. Conclusions Our findings suggest that strong and significant associations exist between autonomy, acceptability of IPVAW and utilization of maternal health-care services.

    更新日期:2019-02-08
  • The impact of bicycle helmet legislation on cycling fatalities in Australia
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-02-05
    Olivier J, Boufous S, Grzebieta R.

    BackgroundAustralian bicycle helmet laws were first introduced in Victoria in July 1990 and the remaining Australian states, Australian Capital Territory and Northern Territory by July 1992. Previous research on helmet legislation has focused on changes in helmet wearing and bicycle-related head injury. Although it is generally accepted that bicycle helmets can reduce the risk of fatality due to head injury, there has been little research assessing the impact of helmet legislation on cycling fatalities.MethodsAn interrupted time series approach was used to assess the impact of bicycle helmet legislation on yearly-aggregated rates of bicycle-related fatalities per population from 1971 to 2016.ResultsImmediately following bicycle helmet legislation, the rate of bicycle fatalities per 1 000 000 population reduced by 46% relative to the pre-legislation trend [95% confidence interval (CI): 31, 58]. For the period 1990–2016, we estimate 1332 fewer cycling fatalities (95% CI: 1201, 1463) or an average of 49.4 per year (95% CI: 44.5, 54.2). Reductions were also observed for pedestrian fatalities; however, bicycle fatalities declined by 36% relative to pedestrian fatalities (95% CI: 12, 54).ConclusionsIn the absence of robust evidence showing a decline in cycling exposure following helmet legislation or other confounding factors, the reduction in Australian bicycle-related fatality appears to be primarily due to increased helmet use and not other factors.

    更新日期:2019-02-07
  • Metformin use and risk of cancer in patients with type 2 diabetes: a cohort study of primary care records using inverse probability weighting of marginal structural models
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-02-06
    Farmer R, Ford D, Mathur R, et al.

    BackgroundPrevious studies provide conflicting evidence on whether metformin is protective against cancer. When studying time-varying exposure to metformin, covariates such as body mass index (BMI) and glycated haemoglobin (HbA1c) may act as both confounders and causal pathway variables, and so cannot be handled adequately by standard regression methods. Marginal structural models (MSMs) with inverse probability of treatment weights (IPTW) can correctly adjust for such confounders. Using this approach, the main objective of this study was to estimate the effect of metformin on cancer risk compared with risk in patients with T2DM taking no medication.MethodsPatients with incident type 2 diabetes (T2DM) were identified in the Clinical Practice Research Datalink (CPRD), a database of electronic health records derived from primary care in the UK. Patients entered the study at diabetes diagnosis or the first point after this when they had valid HbA1c and BMI measurements, and follow-up was split into 1-month intervals. Logistic regression was used to calculate IPTW; then the effect of metformin on all cancers (including and excluding non-melanoma skin cancer) and breast, prostate, lung, colorectal and pancreatic cancers was estimated in the weighted population.ResultsA total of 55 629 T2DM patients were alive and cancer-free at their study entry; 2530 people had incident cancer during a median follow-up time of 2.9 years [interquartile range (IQR) 1.3–5.4 years]. Using the MSM approach, the hazard ratio (HR) for all cancers, comparing treatment with metformin with no glucose-lowering treatment, was 1.02 (0.88–1.18). Results were robust to a range of sensitivity analyses and remained consistent when estimating the treatment effect by length of exposure. We also found no evidence of a protective effect of metformin on individual cancer outcomes.ConclusionsWe find no evidence that metformin has a causal association with cancer risk.

    更新日期:2019-02-07
  • Physical activity of UK adults with chronic disease: cross-sectional analysis of accelerometer-measured physical activity in 96 706 UK Biobank participants
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-02-05
    Barker J, Smith Byrne K, Doherty A, et al.

    Background Physical inactivity is associated with an increased risk of major chronic diseases, although uncertainty exists about which chronic diseases, themselves, might contribute to physical inactivity. The objective of this study was to compare the physical activity of those with chronic diseases to healthy individuals using an objective measure of physical activity. Methods We conducted a cross-sectional analysis of data from 96 706 participants aged 40 years or older from the UK Biobank prospective cohort study (2006–10). Diagnoses were identified through ICD 9 and 10 coding within hospital admission records and a cancer registry linked to UK Biobank participants. We extracted summary physical activity information from participants who wore a wrist-worn triaxial accelerometer for 7 days. Statistical analyses included computation of adjusted geometric means and means using general linear models. Results Participants with chronic disease undertook 9% or 61 minutes (95% confidence interval: 57.8–64.8) less moderate activity and 11% or 3 minutes (95% confidence interval: 2.7–3.3) less vigorous activity per week than individuals without chronic disease. Participants in every chronic-disease subgroup undertook less physical activity than those without chronic disease. Sixty-seven diagnoses within these subgroups were associated with lower moderate activity. Conclusions The cross-sectional association of physical activity with chronic disease is broad. Given the substantial health benefits of being physically active, clinicians and policymakers should be aware that their patients with any chronic disease are at greater health risk from other diseases than anticipated because of their physical inactivity.

    更新日期:2019-02-05
  • Commentary: Triglycerides or HDL cholesterol in cardiovascular disease—which is the true culprit?
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-23
    Varbo A, Nordestgaard B.

    The study by Philips and Davey Smith1 from 1991 addressed the subject of inferring causality from observational epidemiology in situations where exposures are highly correlated and measurement variability is not similar for the variables. The authors exemplified this problem with triglycerides and high-density lipoprotein HDL cholesterol in the risk for cardiovascular disease, with inversely associated concentrations of the two biomarkers and with a higher variability in concentrations of triglycerides than in HDL cholesterol. The association of high concentrations of triglycerides with risk for cardiovascular disease is attenuated when adjusted for HDL cholesterol; however, when adjusting the association of low HDL cholesterol with risk for cardiovascular disease for triglyceride concentrations, the association is not attenuated to the same extent.1 This has previously often led to the interpretation that HDL cholesterol is more important than triglycerides for causing cardiovascular disease. In consequence, huge efforts went into developing and testing HDL cholesterol-raising drugs, which surprisingly did not prevent cardiovascular disease.2

    更新日期:2019-01-28
  • Proof of concept for quantitative urine NMR metabolomics pipeline for large-scale epidemiology and genetics
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-25
    Tynkkynen T, Wang Q, Ekholm J, et al.

    Background Quantitative molecular data from urine are rare in epidemiology and genetics. NMR spectroscopy could provide these data in high throughput, and it has already been applied in epidemiological settings to analyse urine samples. However, quantitative protocols for large-scale applications are not available. Methods We describe in detail how to prepare urine samples and perform NMR experiments to obtain quantitative metabolic information. Semi-automated quantitative line shape fitting analyses were set up for 43 metabolites and applied to data from various analytical test samples and from 1004 individuals from a population-based epidemiological cohort. Novel analyses on how urine metabolites associate with quantitative serum NMR metabolomics data (61 metabolic measures; n = 995) were performed. In addition, confirmatory genome-wide analyses of urine metabolites were conducted (n= 578). The fully automated quantitative regression-based spectral analysis is demonstrated for creatinine and glucose (n = 4548). Results Intra-assay metabolite variations were mostly <5%, indicating high robustness and accuracy of urine NMR spectroscopy methodology per se. Intra-individual metabolite variations were large, ranging from 6% to 194%. However, population-based inter-individual metabolite variations were even larger (from 14% to 1655%), providing a sound base for epidemiological applications. Metabolic associations between urine and serum were found to be clearly weaker than those within serum and within urine, indicating that urinary metabolomics data provide independent metabolic information. Two previous genome-wide hits for formate and 2-hydroxyisobutyrate were replicated at genome-wide significance. Conclusion Quantitative urine metabolomics data suggest broad novelty for systems epidemiology. A roadmap for an open access methodology is provided.

    更新日期:2019-01-28
  • Interaction or mediation by adult obesity of the relation between fetal famine exposure and type 2 diabetes?
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-23
    Li C, Lumey L.

    Prenatal exposure to the Dutch famine has been associated with larger body size in adulthood1 and also with higher risk of type 2 diabetes,2,3 and obesity is a well-established risk factor for diabetes.4 We were therefore intrigued by findings from the important study by Meng et al., that prenatal exposure to the Chinese Great Famine may interact with abdominal obesity [waist-to-hip ratio (WHR) >=0.95 in men and >=0.85 in women] but not with general obesity [body mass index (BMI) >=24.0 kg/m2] in adulthood to increase the risk of diabetes.5 Meng et al. further reported that adjustment for abdominal or general obesity did not much change the association between famine exposure and diabetes, so that ‘adult obesity might not be a mediator of the association’.5 We examined these counter-intuitive findings using data provided with the original report, and suggest their findings should be interpreted otherwise.

    更新日期:2019-01-24
  • Smoking and breast cancer risk by race/ethnicity and oestrogen and progesterone receptor status: the Multiethnic Cohort (MEC) study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-18
    Gram I, Park S, Maskarinec G, et al.

    Background The purpose of this study was to examine if the smoking-related higher breast cancer risk was similar for the five race/ethnicity groups in the Multiethnic Cohort (MEC) study and by oestrogen (ER) and progesterone (PR) receptor status. Methods From 1993 to 2013, we followed 67 313 women who were enrolled in the MEC study at 45–75 years of age. We identified breast cancer cases and tumour receptor status via linkage to the Hawaii and California Surveillance, Epidemiology and End Results Program cancer registries through December 2013. We used Cox proportional hazards regression to estimate multivariable-adjusted hazard ratios with 95% confidence intervals (CI). Results During a mean follow-up of 16.7 years, we identified 4230 incident, invasive breast cancer cases. Compared with parous never smokers, parous ever smokers who had smoked more than 5 years before their first live childbirth had a higher risk of breast cancer overall of 31% (95% CI: 1.14–1.51). This higher risk was 51% (95% CI: 1.05–2.16) for African Americans, 66% (95% CI: 1.10–2.50) for Native Hawaiians, 42% (95% CI: 1.13–1.78) for Whites, 37% (95% CI: 1.17–1.61) for ER-positive (ER+) tumours and 33% (95% CI: 1.11–1.59) for PR+ tumours. No difference was suggested by racial/ethnic groups (Pheterogeneity = 0.15) or tumour receptor status (Pheterogeneity = 0.60 by ER status and 0.95 by PR status). Conclusions We find that the higher breast cancer risk related to smoking is similar across racial/ethnic groups and by ER and PR status, indicating that breast cancer should be considered as a smoking-related cancer.

    更新日期:2019-01-23
  • Reply: Interaction or mediation by adult obesity of the relation between fetal famine exposure and type 2 diabetes?
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-21
    Meng R, Lv J, Li L.

    We thank Dr Li and colleagues for their interest in our study. As mentioned by Li et al., the associations of fetal exposure to famine with adult obesity and diabetes risks have been observed in Dutch famine studies. Also, there is a well-established association between obesity and diabetes. After the combination of non-exposed and early-childhood-exposed participants as the reference, our study reported the similar findings that both fetal exposure to the Chinese Great Famine and adult overweight or obesity were associated with increased risks of type 2 diabetes.1 However, the relations between famine exposure, adult obese status and diabetes risk do not necessarily lead to an interaction between the effects of famine exposure and adult obesity on diabetes risk. Similarly, two previous studies also did not find that general obesity during adulthood interacts with the Chinese famine experience in early life to increase the risk of type 2 diabetes.2,3 To the best of our knowledge, our study is the first to investigate the effect of the interaction of fetal famine exposure with abdominal obesity on diabetes risk.

    更新日期:2019-01-23
  • Association of ten gastrointestinal and other medical conditions with positivity to faecal occult blood testing in routine screening: a large prospective study of women in England
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-21
    He E, Alison R, Blanks R, et al.

    Background In 2006, the Bowel Cancer Screening Programme (BCSP) in England began offering biennial faecal occult blood testing (FOBt) at ages 60–69 years. Although FOBt is aimed at detecting colorectal neoplasms, other conditions can affect the result. In a large UK prospective study, we examined associations, both before and after screening, between FOBt positivity and 10 conditions that are often associated with gastrointestinal bleeding. Methods By electronically linking BCSP and Million Women Study records, we identified 604 495 women without previous colorectal cancer who participated in their first routine FOBt screening between 2006 and 2012. Regression models, using linked national hospital admission records, yielded adjusted relative risks (RRs) in FOBt-positive versus FOBt-negative women for colorectal cancer, adenoma, diverticular disease, inflammatory bowel disease, haemorrhoids, upper gastrointestinal cancer, oesophagitis, peptic ulcer, anaemia and other haematological disorders. Findings RRs in FOBt-positive versus FOBt-negative women were 201.3 (95% CI 173.8–233.2) for colorectal cancer and 197.9 (95% CI 180.6–216.8) for adenoma within 12 months after screening and 3.49 (95% CI 2.31–5.26) and 4.88 (95% CI 3.80–6.26), respectively, 12–24 months after screening; P < 0.001 for all RRs. In the 12 months after screening, the RR for inflammatory bowel disease was 26.3 (95% CI 19.9–34.7), and ranged between 2 and 5 for the upper gastrointestinal or haematological disorders. The RRs of being diagnosed with any of the eight conditions other than colorectal neoplasms before screening, and in the 12–24 months after screening, were 1.81 (95% CI 1.81–2.01) and 1.92 (95% CI 1.66–2.13), respectively. Conclusions Whereas FOBt positivity is associated with a substantially increased risk of colorectal neoplasms after screening, eight other gastrointestinal and haematological conditions are also associated with FOBt positivity, both before and after screening.

    更新日期:2019-01-23
  • Prospective associations of maternal choline status with offspring body composition in the first 5 years of life in two large mother–offspring cohorts: the Southampton Women’s Survey cohort and the Growing Up in Singapore Towards healthy Outcomes cohort
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-11
    van Lee L, Crozier S, Aris I, et al.

    Background Choline status has been positively associated with weight and fat mass in animal and human studies. As evidence examining maternal circulating choline concentrations and offspring body composition in human infants/children is lacking, we investigated this in two cohorts. Methods Maternal choline concentrations were measured in the UK Southampton Women’s Survey (SWS; serum, n = 985, 11 weeks’ gestation) and Singapore Growing Up Towards healthy Outcomes (GUSTO); n = 955, 26–28 weeks’ gestation) mother–offspring cohorts. Offspring anthropometry was measured at birth and up to age 5 years. Body fat mass was determined using dual-energy x-ray absorptiometry at birth and age 4 years for SWS; and using air-displacement plethysmography at birth and age 5 years for GUSTO. Linear-regression analyses were performed, adjusting for confounders. Results In SWS, higher maternal choline concentrations were associated with higher neonatal total body fat mass {β = 0.60 standard deviation [SD]/5 µmol/L maternal choline [95% confidence interval (CI) 0.04–1.16]} and higher subscapular skinfold thickness [β = 0.55 mm/5 µmol/L (95% CI, 0.12–1.00)] at birth. In GUSTO, higher maternal choline concentrations were associated with higher neonatal body mass index-for-age z-score [β = 0.31 SD/5 µmol/L (0.10–0.51)] and higher triceps [β = 0.38 mm/5 µmol/L (95% CI, 0.11–0.65)] and subscapular skinfold thicknesses [β = 0.26 mm/5 µmol/L (95% CI, 0.01–0.50)] at birth. No consistent trends were observed between maternal choline and offspring gain in body mass index, skinfold thicknesses, abdominal circumference, weight, length/height and adiposity measures in later infancy and early childhood. Conclusion Our study provides evidence that maternal circulating choline concentrations during pregnancy are positively associated with offspring BMI, skinfold thicknesses and adiposity at birth, but not with growth and adiposity through infancy and early childhood to the age of 5 years.

    更新日期:2019-01-13
  • Patterns of body mass index milestones in early life and cardiometabolic risk in early adolescence
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-08
    Aris I, Rifas-Shiman S, Li L, et al.

    Bac kground Few studies have examined the independent and combined relationships of body mass index (BMI) peak and rebound with adiposity, insulin resistance and metabolic risk later in life. We used data from Project Viva, a well-characterized birth cohort from Boston with repeated measures of BMI, to help fill this gap. Methods Among 1681 children with BMI data from birth to mid childhood, we fitted individual BMI trajectories using mixed-effects models with natural cubic splines and estimated age, and magnitude of BMI, at peak (in infancy) and rebound (in early childhood). We obtained cardiometabolic measures of the children in early adolescence (median 12.9 years) and analysed their associations with the BMI parameters. Results After adjusting for potential confounders, age and magnitude at infancy BMI peak were associated with greater adolescent adiposity, and earlier adiposity rebound was strongly associated with greater adiposity, insulin resistance and metabolic risk score independently of BMI peak. Children with a normal timing of BMI peak plus early rebound had an adverse cardiometabolic profile, characterized by higher fat mass index {β 2.2 kg/m2 [95% confidence interval (CI) 1.6, 2.9]}, trunk fat mass index [1.1 kg/m2 (0.8, 1.5)], insulin resistance [0.2 units (0.04, 0.4)] and metabolic risk score [0.4 units (0.2, 0.5)] compared with children with a normal BMI peak and a normal rebound pattern. Children without a BMI peak (no decline in BMI after the rise in infancy) also had adverse adolescent metabolic profiles. Conclusions Early age at BMI rebound is a strong risk factor for cardiometabolic risk, independent of BMI peak. Children with a normal peak-early rebound pattern, or without any BMI decline following infancy, are at greatest risk of adverse cardiometabolic profile in adolescence. Routine monitoring of BMI may help to identify children who are at greatest risk of developing an adverse cardiometabolic profile in later life and who may be targeted for preventive interventions.

    更新日期:2019-01-09
  • Reflection on modern methods: years of life lost due to premature mortality—a versatile and comprehensive measure for monitoring non-communicable disease mortality
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-09
    Martinez R, Soliz P, Caixeta R, et al.

    The analysis of causes impacting on premature mortality is an essential function of public health surveillance. Diverse methods have been used for accurately assessing and reporting the level and trends of premature mortality; however, many have important limitations, particularly in capturing actual early deaths. We argue that the framework of years of life lost (YLL), as conceptualized in disability-adjusted life-years (DALYs), is a robust and comprehensive measure of premature mortality. Global Burden of Disease study is systematically providing estimates of YLL; however, it is not widely adopted at country level, among other reasons because its conceptual and methodological bases seem to be not sufficiently known and understood. In this paper, we provide the concepts and the methodology of the YLL framework, including the selection of the loss of function that defines the time lost due to premature deaths, and detailed methods for calculating YLL metrics. We also illustrate how to use YLL to quantify the level and trends of premature non-communicable disease (NCD) mortality in the Americas. The tutorial style of the illustrative example is intended to educate the public health community and stimulate the use of YLL in disease prevention and control programmes at different levels.

    更新日期:2019-01-09
  • Welfare regimes modify the association of disadvantaged adult-life socioeconomic circumstances with self-rated health in old age
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2019-01-03
    Sieber S, Cheval B, Orsholits D, et al.

    Background Welfare regimes in Europe modify individuals’ socioeconomic trajectories over their life-course, and, ultimately, the link between socioeconomic circumstances (SECs) and health. This paper aimed to assess whether the associations between life-course SECs (early-life, young adult-life, middle-age and old-age) and risk of poor self-rated health (SRH) trajectories in old age are modified by welfare regimes (Scandinavian [SC], Bismarckian [BM], Southern European [SE], Eastern European [EE]). Methods We used data from the longitudinal SHARE survey. Early-life SECs consisted of four indicators of living conditions at age 10. Young adult-life, middle-age, and old-age SECs indicators were education, main occupation and satisfaction with household income, respectively. The association of life-course SECs with poor SRH trajectories was analysed by confounder-adjusted multilevel logistic regression models stratified by welfare regime. We included 24 011 participants (3626 in SC, 10 256 in BM, 6891 in SE, 3238 in EE) aged 50 to 96 years from 13 European countries. Results The risk of poor SRH increased gradually with early-life SECs from most advantaged to most disadvantaged. The addition of adult-life SECs differentially attenuated the association of early-life SECs and SRH at older age across regimes: education attenuated the association only in SC and SE regimes and occupation only in SC and BM regimes; satisfaction with household income attenuated the association across regimes. Conclusions Early-life SECs have a long-lasting effect on SRH in all welfare regimes. Adult-life SECs attenuated this influence differently across welfare regimes.

    更新日期:2019-01-04
  • Circulating vitamin D concentrations and risk of breast and prostate cancer: a Mendelian randomization study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-28
    Jiang X, Dimou N, Al-Dabhani K, et al.

    Background Observational studies have suggested an association between circulating vitamin D concentrations [25(OH)D] and risk of breast and prostate cancer, which was not supported by a recent Mendelian randomization (MR) analysis comprising 15 748 breast and 22 898 prostate-cancer cases. Demonstrating causality has proven challenging and one common limitation of MR studies is insufficient power. Methods We aimed to determine whether circulating concentrations of vitamin D are causally associated with the risk of breast and prostate cancer, by using summary-level data from the largest ever genome-wide association studies conducted on vitamin D (N = 73 699), breast cancer (Ncase = 122 977) and prostate cancer (Ncase = 79 148). We constructed a stronger instrument using six common genetic variants (compared with the previous four variants) and applied several two-sample MR methods. Results We found no evidence to support a causal association between 25(OH)D and risk of breast cancer [OR per 25 nmol/L increase, 1.02 (95% confidence interval: 0.97–1.08), P = 0.47], oestrogen receptor (ER)+ [1.00 (0.94–1.07), P = 0.99] or ER− [1.02 (0.90–1.16), P = 0.75] subsets, prostate cancer [1.00 (0.93–1.07), P = 0.99] or the advanced subtype [1.02 (0.90–1.16), P = 0.72] using the inverse-variance-weighted method. Sensitivity analyses did not reveal any sign of directional pleiotropy. Conclusions Despite its almost five-fold augmented sample size and substantially improved statistical power, our MR analysis does not support a causal effect of circulating 25(OH)D concentrations on breast- or prostate-cancer risk. However, we can still not exclude a modest or non-linear effect of vitamin D. Future studies may be designed to understand the effect of vitamin D in subpopulations with a profound deficiency.

    更新日期:2019-01-01
  • The contribution of drug-related deaths to the US disadvantage in mortality
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-28
    Barbieri M.

    Background The USA ranks last in life expectancy among high-income countries. Since 2000, excess US mortality has been particularly concentrated in the working ages, which are also the ages hardest hit by the increase in drug deaths. This study measures the effect of drug-related mortality on the gap in life expectancy between the USA and other countries. Methods Data from the Human Mortality Database and the World Health Organization were combined to construct age-standardized mortality rates for 2000–14 in 12 high-income countries and the USA for seven broad causes of death, including drug use. The contribution of each cause to the difference in life expectancy between the USA and the other 12 countries was estimated. Results In 2014, the increase in drug-related deaths accounted for 10–15% of the US disadvantage in mortality, but with marked differences by age group. For working-age men, the increase in drug-related deaths accounted for up to 38% of the difference. Overall, American mortality is higher than the comparison countries across a wide range of causes. Conclusions The severity of the drug epidemic appears to be specific to the USA, but it only partly contributes to the American shortfall in mortality.

    更新日期:2019-01-01
  • Poor diet quality in pregnancy is associated with increased risk of excess fetal growth: a prospective multi-racial/ethnic cohort study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-26
    Zhu Y, Hedderson M, Sridhar S, et al.

    Background Nutritional perturbations during pregnancy may impact fetal and long-term childhood growth, although there are limited data on overall diet quality. We investigated whether diet quality, measured by the Healthy Eating Index-2010 (HEI-2010), during pregnancy was related to birthweight z-score (BWZ) and the clinically relevant birth outcomes of large- and small-for-gestational age (LGA and SGA). Methods In a prospective cohort of 2269 multi-racial/ethnic women from the Pregnancy Environment and Lifestyle Study (2014–2017), dietary intake was assessed by a food frequency questionnaire during early pregnancy. Offspring BWZ and LGA or SGA were derived based on gestational age-, sex-, and racial/ethnic-specific birthweight distributions. Multivariable linear and Poisson regression with robust standard errors were used. Results About 80% of women did not achieve good diet quality (HEI-2010 < 80). After adjusting for covariates, infants born to women in the lowest vs highest quartile of HEI-2010 (37.5–64.4 vs 78.7–94.2) had a 0.12 standard-deviation [95% confidence interval (CI) 0.01–0.23, P-for-trend = 0.023] greater BWZ and 1.76-fold (1.08–2.87, P-for-trend = 0.037) increased risk of LGA. No association was observed between HEI-2010 and SGA. Per-5-point substitution of the reversely coded empty calories component score with the whole grains component score in the HEI-2010 was related to a 25% (95% CI 0.66–0.86) lower risk of LGA. Conclusions Poor diet quality in pregnancy was associated with higher birthweight and increased risk of LGA independent of maternal obesity and other covariates. Substitution of empty calories with whole grains may mitigate the risk of excess fetal growth. Our findings may inform potential prevention strategies and dietary guidelines for pregnant women.

    更新日期:2018-12-28
  • Socioeconomic position during pregnancy and DNA methylation signatures at three stages across early life: epigenome-wide association studies in the ALSPAC birth cohort
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-22
    Alfano R, Guida F, Galobardes B, et al.

    Background Socioeconomic experiences are recognized determinants of health, and recent work has shown that social disadvantages in early life may induce sustained biological changes at molecular level that are detectable later in life. However, the dynamics and persistence of biological embedding of socioeconomic position (SEP) remains vastly unexplored. Methods Using the data from the ALSPAC birth cohort, we performed epigenome-wide association studies of DNA methylation changes at three life stages (birth, n = 914; childhood at mean age 7.5 years, n = 973; and adolescence at mean age 15.5 years, n= 974), measured using the Illumina HumanMethylation450 Beadchip, in relation to pregnancy SEP indicators (maternal and paternal education and occupation). Results Across the four early life SEP metrics investigated, only maternal education was associated with methylation levels at birth, and four CpGs mapped to SULF1, GLB1L2 and RPUSD1 genes were identified [false discovery rate (FDR)-corrected P-value <0.05]. No epigenetic signature was found associated with maternal education in child samples, but methylation levels at 20 CpG loci were found significantly associated with maternal education in adolescence. Although no overlap was found between the differentially methylated CpG sites at different ages, we identified two CpG sites at birth and during adolescence which are 219 bp apart in the SULF1 gene that encodes an heparan sulphatase involved in modulation of signalling pathways. Using data from an independent birth cohort, the ENVIRONAGE cohort, we were not able to replicate these findings. Conclusions Taken together, our results suggest that parental SEP, and particularly maternal education, may influence the offspring’s methylome at birth and adolescence.

    更新日期:2018-12-25
  • Improving the accuracy of two-sample summary-data Mendelian randomization: moving beyond the NOME assumption
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-18
    Bowden J, Del Greco M F, Minelli C, et al.

    Background Two-sample summary-data Mendelian randomization (MR) incorporating multiple genetic variants within a meta-analysis framework is a popular technique for assessing causality in epidemiology. If all genetic variants satisfy the instrumental variable (IV) and necessary modelling assumptions, then their individual ratio estimates of causal effect should be homogeneous. Observed heterogeneity signals that one or more of these assumptions could have been violated. Methods Causal estimation and heterogeneity assessment in MR require an approximation for the variance, or equivalently the inverse-variance weight, of each ratio estimate. We show that the most popular ‘first-order’ weights can lead to an inflation in the chances of detecting heterogeneity when in fact it is not present. Conversely, ostensibly more accurate ‘second-order’ weights can dramatically increase the chances of failing to detect heterogeneity when it is truly present. We derive modified weights to mitigate both of these adverse effects. Results Using Monte Carlo simulations, we show that the modified weights outperform first- and second-order weights in terms of heterogeneity quantification. Modified weights are also shown to remove the phenomenon of regression dilution bias in MR estimates obtained from weak instruments, unlike those obtained using first- and second-order weights. However, with small numbers of weak instruments, this comes at the cost of a reduction in estimate precision and power to detect a causal effect compared with first-order weighting. Moreover, first-order weights always furnish unbiased estimates and preserve the type I error rate under the causal null. We illustrate the utility of the new method using data from a recent two-sample summary-data MR analysis to assess the causal role of systolic blood pressure on coronary heart disease risk. Conclusions We propose the use of modified weights within two-sample summary-data MR studies for accurately quantifying heterogeneity and detecting outliers in the presence of weak instruments. Modified weights also have an important role to play in terms of causal estimation (in tandem with first-order weights) but further research is required to understand their strengths and weaknesses in specific settings.

    更新日期:2018-12-18
  • Shedding light on the link between early life sun exposure and risk of multiple sclerosis: results from the EnvIMS Study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-18
    Magalhaes S, Pugliatti M, Riise T, et al.

    Background Lower levels of sun exposure in childhood have been suggested to be associated with increased risk of multiple sclerosis (MS). In this paper we extend previous work, using two novel analytical strategies. Methods Data collected in the Environmental risk factors In MS (EnvIMS) study, a case-control study with MS cases and population-based controls from Canada, Italy and Norway, were used. Participants reported on sun exposure behaviours for 5-year age intervals from birth; we focused on the first three age intervals (≤15 years). We compared two life course epidemiology conceptual models, the critical period and the accumulation model. We also used latent class analysis to estimate MS risk for different latent sun exposure behaviour groups. Results The analyses included 2251 cases and 4028 controls. The accumulation model was found to be the best model, which demonstrated a nearly 50% increased risk of MS comparing lowest reported summer sun exposure with highest [risk ratio (RR) = 1.47 (1.24, 1.74)]. The latent sun exposure behaviour group, characterized by low sun exposure during summer and winter and high sun protection use, had the highest risk of MS; a 76% increased risk as compared with the group with high sun exposure and low sun protection use [RR = 1.76 (1.27, 2.46)]. Conclusions Our analyses provide novel insights into the link between sun exposure and MS. We demonstrate that more time indoors during childhood and early adolescence is linked with MS risk, and that sun protection behaviours in those who spend most time indoors may play a key role in increasing risk.

    更新日期:2018-12-18
  • Educational Note: Paradoxical collider effect in the analysis of non-communicable disease epidemiological data: a reproducible illustration and web application
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-14
    Luque-Fernandez M, Schomaker M, Redondo-Sanchez D, et al.

    Classical epidemiology has focused on the control of confounding, but it is only recently that epidemiologists have started to focus on the bias produced by colliders. A collider for a certain pair of variables (e.g. an outcome Y and an exposure A) is a third variable (C) that is caused by both. In a directed acyclic graph (DAG), a collider is the variable in the middle of an inverted fork (i.e. the variable C in A → C ← Y). Controlling for, or conditioning an analysis on a collider (i.e. through stratification or regression) can introduce a spurious association between its causes. This potentially explains many paradoxical findings in the medical literature, where established risk factors for a particular outcome appear protective. We use an example from non-communicable disease epidemiology to contextualize and explain the effect of conditioning on a collider. We generate a dataset with 1000 observations, and run Monte-Carlo simulations to estimate the effect of 24-h dietary sodium intake on systolic blood pressure, controlling for age, which acts as a confounder, and 24-h urinary protein excretion, which acts as a collider. We illustrate how adding a collider to a regression model introduces bias. Thus, to prevent paradoxical associations, epidemiologists estimating causal effects should be wary of conditioning on colliders. We provide R code in easy-to-read boxes throughout the manuscript, and a GitHub repository [https://github.com/migariane/ColliderApp] for the reader to reproduce our example. We also provide an educational web application allowing real-time interaction to visualize the paradoxical effect of conditioning on a collider [http://watzilei.com/shiny/collider/].

    更新日期:2018-12-17
  • Precision nutrition: hype or hope for public health interventions to reduce obesity?
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-12
    Chatelan A, Bochud M, Frohlich K.

    High-income countries are experiencing an obesity epidemic that follows a socioeconomic gradient, affecting groups of lower socioeconomic status disproportionately. Recent clinical findings have suggested new perspectives for the prevention and treatment of obesity, using personalized dietary approaches. Precision nutrition (PN), also called personalized nutrition, has been developed to deliver more preventive and practical dietary advice than ‘one-size-fits-all’ guidelines. With interventions becoming increasingly plausible at a large scale thanks to artificial intelligence and smartphone applications, some have begun to view PN as a novel way to deliver the right dietary intervention to the right population. We argue that large-scale PN, if taken alone, might be of limited interest from a public health perspective. Building on Geoffrey Rose’s theory regarding the differences in individual and population causes of disease, we show that large-scale PN can only address some individual causes of obesity (causes of cases). This individual-centred approach is likely to have a small impact on the distribution of obesity at a population level because it ignores the population causes of obesity (causes of incidence). The latter are embedded in the populations’ social, cultural, economic and political contexts that make environments obesogenic. Additionally, the most socially privileged groups in the population are the most likely to respond to large-scale PN interventions. This could have the undesirable effect of widening social inequalities in obesity. We caution public health actors that interventions based only on large-scale PN are unlikely, despite current expectations, to improve dietary intake or reduce obesity at a population level.

    更新日期:2018-12-14
  • Dietary intake of nutrients involved in folate-mediated one-carbon metabolism and risk for endometrial cancer
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-13
    Lu J, Trabert B, Liao L, et al.

    Background Studies disagree as to whether intakes of folate-mediated one-carbon metabolism nutrients are associated with endometrial cancer. Methods Using data from the large, prospective NIH-AARP Diet and Health Study, we used Cox proportional hazards models to evaluate endometrial cancer risk associated with calorie-adjusted dietary intake of several B vitamins and methionine. All models accounted for age, race, body mass index (BMI), smoking, oral-contraceptive use, menopausal hormone therapy use and caloric intake. We estimated associations by time from baseline (≤3 or >3 years) and stratified models by BMI (<25 or ≥25 kg/m2). During 16 years of follow-up, we identified 2329 endometrial cancer cases among 114 414 participants. Results After adjustment for confounding, we observed increased risk for endometrial cancer with greater consumption of dietary total folate, natural folate, B2, B6 and B12 [hazard ratios (HRs) ranging from 1.14 to 1.24 for the highest quintile (Q5) vs the lowest (Q1)]. Higher intakes of total folate, natural folate, B6 and B12 continued to be associated with increased risk when limiting follow-up to >3 years from baseline. We observed risks for the highest intakes of B2 [Q5 vs Q1: HR 1.27 95% confidence interval (CI) 1.07–1.50], B12 (Q5 vs Q1: HR 1.38 CI 1.17–1.63) and methionine (Q5 vs Q1: HR 1.26 CI 1.07–1.48) among women who were overweight/obese, but not among normal/underweight women. Conclusions Our findings indicate that one-carbon metabolism plays a role in endometrial carcinogenesis and exploration of this role in tissue and cellular biology studies is warranted.

    更新日期:2018-12-14
  • Mean and variance of greenness and pregnancy outcomes in Tel Aviv during 2000–14: longitudinal and cross-sectional approaches
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-13
    Agay-Shay K, Michael Y, Basagaña X, et al.

    Background Natural environments may have beneficial impacts on pregnancy outcomes. However, longitudinal evidence is limited and the associations with variance in surrounding greenness is unknown. Our objective was to evaluate these associations among 73 221 live births in Tel Aviv, Israel. Methods Longitudinal exposure to mean of greenness during pregnancy and trimesters were calculated using satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) Normalised Difference Vegetation Index (NDVI) data. In addition, exposure to mean and variation of NDVI from high-resolution satellite and percentage of tree cover [Vegetation Continuous Fields (VCF)] at 300-m buffer were evaluated in a cross-sectional approach. Generalized linear models were used to estimate the crude and adjusted associations. We explore the possible mediating role of ambient exposures and distance to ‘outdoor gyms’ located in parks. Results Crude beneficial associations between exposure to higher mean NDVI during pregnancy and pregnancy outcomes were observed [for birthweight, 3rd/1st tertile exposure increased the mean by 25.5 g, 95% confidence intervals (CIs): 15.4, 35.5] and decreased the odds of low birthweight, small for gestational age, preterm deliveries (PTD) and very PTD. Adjustment for individual and neighbourhood-level markers of socio-economic status (SES) attenuated all the associations. Strongest associations were observed during the first and second trimesters. Cross-sectional associations for mean greenness were similar with narrower CIs, and associations with NDVI were stronger than with tree cover and stronger for mean compared with variance of greenness. Associations were consistent for term births, different buffer sizes and for further adjustment to maternal education. Stronger associations were observed for lowest SES. Distance to ‘outdoor gyms’ and variance of greenness had the largest estimates of mediation. Conclusion This study adds to the limited information on when exposure to greenness is most beneficial, on the association with variance of greenness and the possible pathways. These observations require confirmation in other populations.

    更新日期:2018-12-14
  • Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: results from a collaborative meta-analysis
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-11
    Hartwig F, Davies N, Horta B, et al.

    Background Accumulating evidence suggests that breastfeeding benefits children’s intelligence, possibly due to long-chain polyunsaturated fatty acids (LC-PUFAs) present in breast milk. Under a nutritional adequacy hypothesis, an interaction between breastfeeding and genetic variants associated with endogenous LC-PUFAs synthesis might be expected. However, the literature on this topic is controversial. Methods We investigated this gene × environment interaction through a collaborative effort. The primary analysis involved >12 000 individuals and used ever breastfeeding, FADS2 polymorphisms rs174575 and rs1535 coded assuming a recessive effect of the G allele, and intelligence quotient (IQ) in Z scores. Results There was no strong evidence of interaction, with pooled covariate-adjusted interaction coefficients (i.e. difference between genetic groups of the difference in IQ Z scores comparing ever with never breastfed individuals) of 0.12[(95% confidence interval (CI): −0.19; 0.43] and 0.06 (95% CI: −0.16; 0.27) for the rs174575 and rs1535 variants, respectively. Secondary analyses corroborated these results. In studies with ≥5.85 and <5.85 months of breastfeeding duration, pooled estimates for the rs174575 variant were 0.50 (95% CI: −0.06; 1.06) and 0.14 (95% CI: −0.10; 0.38), respectively, and 0.27 (95% CI: −0.28; 0.82) and −0.01 (95% CI: −0.19; 0.16) for the rs1535 variant. Conclusions Our findings did not support an interaction between ever breastfeeding and FADS2 polymorphisms. However, subgroup analysis suggested that breastfeeding may supply LC-PUFAs requirements for cognitive development if breastfeeding lasts for some (currently unknown) time. Future studies in large individual-level datasets would allow properly powered subgroup analyses and further improve our understanding on the breastfeeding × FADS2 interaction.

    更新日期:2018-12-12
  • Health care systems: future predictions for global care. Jeffrey Braithwaite, Russell Mannion, Yukihiro Matsuyama, Paul G. Shekelle, Stuart Whittaker and Samir Al-Adawi (eds). 1st edition
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-11
    Greenhalgh T.

    Health care systems: future predictions for global care.BraithwaiteJeffrey, MannionRussell, MatsuyamaYukihiro, ShekellePaul G., WhittakerStuart and Al-AdawiSamir (eds). 1st edition. Boca Raton, FL: CRC Press, 15 May 2018, pp. 536, £115, ISBN 9781138052604

    更新日期:2018-12-12
  • Examining associations between physical activity and cardiovascular mortality using negative control outcomes
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-11
    Hamer M, Bauman A, Bell J, et al.

    Background The purpose of a negative control is to reproduce a condition that cannot involve the hypothesized causal mechanism, but does involve the same sources of bias and confounding that may distort the primary association of interest. Observational studies suggest physical inactivity is a major risk factor for cardiovascular disease (CVD), although potential sources of bias, including reverse causation and residual confounding, make it difficult to infer causality. The aim was to employ a negative control outcome to explore the extent to which the association between physical activity and CVD mortality is explained by confounding. Methods The sample comprised 104 851 participants (aged 47 ± 17 years; 45.4% male) followed up over mean (SD) 9.4 ± 4.5 years, recruited from the Health Survey for England and the Scottish Health Survey. Results There were 10 309 deaths, of which 3109 were attributed to CVD and 157 to accidents (negative control outcome). Accidental death was related to age, male sex, smoking, longstanding illness and psychological distress, with some evidence of social patterning. This confounding structure was similar to that seen with CVD mortality, suggesting that our negative control outcome was appropriate. Physical activity (per SD unit increase in MET-hr-wk) was inversely associated with CVD [hazard ratio (HR) = 0.75; 95% confidence interval (CI), 0.70, 0.80]; the point estimate between physical activity and accidental death was in the same direction but of lesser magnitude (HR = 0.86; 95% CI: 0.69, 1.07). A linear dose–response pattern was observed for physical activity and CVD but not with the negative control. Conclusions Inverse associations between physical activity and risk of CVD mortality are likely causal but of a smaller magnitude than commonly observed. Negative control studies have the potential to improve causal inference within the physical activity field.

    更新日期:2018-12-12
  • Sexual mixing in opposite-sex partnerships in Britain and its implications for STI risk: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-11
    Geary R, Copas A, Sonnenberg P, et al.

    Background The extent to which individuals are similar to their sexual partners influences STI-transmission probabilities, yet there is a dearth of empirical data, especially those representative of the population. Methods Analyses of data reported by 10 759 sexually active people aged 16–74 y interviewed for a British national probability survey undertaken in 2010–12. Computer-assisted self-interviews asked about partner numbers and characteristics of participants’ three most recent partnerships (MRPs). Opposite-sex MRPs were weighted to represent all such partnerships in the past year (N = 16 451). Estimates of disassortative age mixing (≥±5-y difference), ethnic mixing (partner of a different ethnic group) and geographical mixing (partner from a different region/country when they first met) were calculated, stratified by gender, age group and partnership status (casual/steady). Multivariable regression examined how these disassortative mixing measures were associated with STI-risk measures: condom use at first sex together at the partnership-level and, at the participant-level, STI-risk perception and reporting STI diagnoses. Results Disassortative age mixing occurred in around one-third of opposite-sex partnerships, with men ≥5 y older in most cases, although this proportion varied by participant’s gender and age group. Ethnic mixing occurred less frequently (11.3% of men’s and 8.6% of women’s partnerships) as did geographical mixing (14.1 and 16.3%, respectively). Disassortative mixing was more common among casual vs steady partnerships. Condom use at first sex was less likely in women’s partnerships that were age-disassortative [adjusted odds ratio (AOR): 0.79, 95% confidence interval (CI): 0.69–0.95], whereas men reporting disassortative ethnic mixing were more likely to perceive themselves at STI risk (AOR: 1.76, 95% CI: 1.23–2.52) and report STI diagnoses (AOR: 2.37, 95% CI: 1.22–4.59). Conclusions Disassortative mixing, although uncommon among opposite-sex partnerships in Britain, is independently associated with STI risk, warranting consideration in STI-prevention efforts.

    更新日期:2018-12-12
  • An examination of multivariable Mendelian randomization in the single-sample and two-sample summary data settings
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-10
    Sanderson E, Davey Smith G, Windmeijer F, et al.

    Background Mendelian randomization (MR) is a powerful tool in epidemiology that can be used to estimate the causal effect of an exposure on an outcome in the presence of unobserved confounding, by utilizing genetic variants that are instrumental variables (IVs) for the exposure. This has been extended to multivariable MR (MVMR) to estimate the effect of two or more exposures on an outcome. Methods and results We use simulations and theory to clarify the interpretation of estimated effects in a MVMR analysis under a range of underlying scenarios, where a secondary exposure acts variously as a confounder, a mediator, a pleiotropic pathway and a collider. We then describe how instrument strength and validity can be assessed for an MVMR analysis in the single-sample setting, and develop tests to assess these assumptions in the popular two-sample summary data setting. We illustrate our methods using data from UK Biobank to estimate the effect of education and cognitive ability on body mass index. Conclusion MVMR analysis consistently estimates the direct causal effect of an exposure, or exposures, of interest and provides a powerful tool for determining causal effects in a wide range of scenarios with either individual- or summary-level data.

    更新日期:2018-12-11
  • Handwashing with soap after potential faecal contactGlobal, regional and country estimates for handwashing with soap after potential faecal contact
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-10
    Wolf J, Johnston R, Freeman M, et al.

    Background Limited data have been available on the global practice of handwashing with soap (HWWS). To better appreciate global HWWS frequency, which plays a role in disease transmission, our objectives were to: (i) quantify the presence of designated handwashing facilities; (ii) assess the association between handwashing facility presence and observed HWWS; and (iii) derive country, regional and global HWWS estimates after potential faecal contact. Methods First, using data from national surveys, we applied multilevel linear modelling to estimate national handwashing facility presence. Second, using multilevel Poisson modelling on datasets including both handwashing facility presence and observed HWWS after potential faecal contact, we estimated HWWS prevalence conditional on handwashing facility presence by region. For high-income countries, we used meta-analysis to pool handwashing prevalence of studies identified through a systematic review. Third, from the modelled handwashing facility presence and estimated HWWS prevalence conditional on the presence of a handwashing facility, we estimated handwashing practice at country, regional and global levels. Results First, approximately one in four persons did not have a designated handwashing facility in 2015, based on 115 data points for 77 countries. Second the prevalence ratio between HWWS when a designated facility was present compared with when it was absent was 1.99 (1.66, 2.39) P <0.001 for low- and middle-income countries, based on nine datasets. Third, we estimate that in 2015, 26.2% (23.1%, 29.6%) of potential faecal contacts were followed by HWWS. Conclusions Many people lack a designated handwashing facility, but even among those with access, HWWS is poorly practised. People with access to designated handwashing facilities are about twice as likely to wash their hands with soap after potential faecal contact as people who lack a facility. Estimates are based on limited data.

    更新日期:2018-12-11
  • Epidemiology at a time for unity
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-11
    Lau B, Duggal P, Ehrhardt S.

    There was a reference citation error in Table 1 on page 1369 of this article. The table title incorrectly cited reference 42; it should cite reference 43, by Pearce. The article has been corrected.

    更新日期:2018-12-11
  • Association between physical activity and scoliosis: a prospective cohort study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-06
    Tobias J, Fairbank J, Harding I, et al.

    Background Little is understood about the causes of adolescent onset idiopathic scoliosis (AIS). No prospective studies assessing the association between physical activity and idiopathic adolescent scoliosis have been carried out. We aimed to carry out the first prospective population-based study of this association. Methods The Avon Longitudinal Study of Parents and Children (ALSPAC) collected self-reported measures of physical ability/activity at ages 18 months and 10 years. Objective measures of physical activity were collected by accelerometry at age 11 years. scoliosis was identified using the dxa scoliosis Method at age 15 years. Participants with scoliosis at age 10 years were excluded. Results Of 4640 participants at age 15 years who had DXA scans, 267 (5.8%) had scoliosis. At age 18 months, those infants who were able to stand up without being supported were 66% less likely to have developed scoliosis by age 15 (P = 0.030) compared with infants who could not. Those children whose mothers reported they did most vigorous physical activity at age 10 years were 53% less likely to develop scoliosis (P = 0.027). Those children who did more objectively measured moderate/vigorous physical activity at age 11 were 30% less likely to have developed scoliosis (P < 0.001). Results were not affected by adjustment for age, gender, lean mass, fat mass or back pain. Conclusions We report reduced physical ability and activity as early as age 18 months in those who go on to develop scoliosis by age 15 years. Further research is justified to examine the mechanisms underlying this association.

    更新日期:2018-12-07
  • Use of a pooled cohort to impute cardiovascular disease risk factors across the adult life course
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-07
    Zeki Al Hazzouri A, Vittinghoff E, Zhang Y, et al.

    Background In designing prevention strategies, it may be useful to understand how early and midlife cardiovascular disease risk factor (CVDRF) exposures affect outcomes that primarily occur in mid to late life. Few single US cohorts have followed participants from early adulthood to late life. Methods We pooled four prospective cohorts that represent segments of the adult life course, and studied 15 001 White and Black adults aged 18 to 95 years at enrollment. We imputed early and midlife exposure to body mass index (BMI), glucose, lipids and blood pressure (BP). CVDRF trajectories were estimated using linear mixed models. Using the best linear unbiased predictions, we obtained person-specific estimates of CVDRF trajectories beginning at age 20 until each participant’s end of follow-up. We then calculated for each CVDRF, summary measures of early and midlife exposure as time-weighted averages (TWAs). Results In the pooled cohort, 33.7% were Black and 54.8% were female. CVDRF summary measures worsened in midlife compared with early life and varied by sex and race. In particular, systolic and diastolic BP were consistently higher over the adult life course among men, and BMI was higher among Blacks, particularly Black women. Simulation studies suggested acceptable imputation accuracy, especially for the younger cohorts. Correlations of true and imputed CVDRF summary measures ranged from 0.53 to 0.99, and agreement ranged from 67% to 99%. Conclusions These results suggest that imputed CVDRFs may be accurate enough to be useful in assessing the effects of early and midlife exposures on later life outcomes.

    更新日期:2018-12-07
  • What if all children achieved WHO recommendations on physical activity? Estimating the impact on socioeconomic inequalities in childhood overweight in the UK Millennium Cohort Study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-12-07
    Pearce A, Hope S, Griffiths L, et al.

    Background The World Health organization (WHO) recommends that children engage in 60 min daily moderate-to-vigorous physical activity (dMVPA). Just half of children in the UK achieve these levels (with similarly low levels in other high-income countries). Thus, the dMVPA target is a focus of national obesity strategies. However, the potential impact of increased physical activity on prevalence and inequalities in childhood overweight is unknown. Using objective data from the Millennium Cohort Study (∼18 000 children born 2000–02) we simulated a series of hypothetical physical activity intervention scenarios: achievement of the target, and more realistic increases demonstrated in trials. Methods Predicted probabilities of overweight and obesity (using measured heights and weights at age 11) were estimated in multinomial marginal structural models, adjusting for dMVPA (measured with accelerometers at age 7) and confounding. Inequalities were assessed according to household income quintiles [risk ratios (RRs) and risk differences (RDs)]. Intervention scenarios were simulated by re-estimating predicted probabilities of overweight/obesity after manipulating (increasing) dMVPA by varying amounts, for different eligibility criteria and with varying uptake. Analyses included 6493 children with accelerometer data. Survey weights and multiple imputation addressed sampling design, attrition and item missingness. Results In all, 27% children were overweight/obese, with relative and absolute inequalities in the expected direction; 51% children were achieving 60 min dMVPA, with those from the lowest income quintile achieving, on average, 3 min more dMVPA than those from the highest income quintile. A simulation of universal achievement of the dMVPA target reduced the prevalence of overweight/obesity to 22%, but increased relative inequalities (absolute inequalities were unchanged). Smaller increases in dMVPA (informed by intervention evidence) did little to reduce prevalence or inequalities, even when targeting high-risk groups. Conclusions Universal achievement of the WHO dMVPA target, if attainable, would reduce prevalence of childhood overweight and obesity but not inequalities. Scale-up of more realistic interventions would have limited impact.

    更新日期:2018-12-07
  • Data Resource Profile: The China National Health Survey (CNHS)
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2014-08-13
    He H, Pan L, Pa L, et al.

    The China National Health Survey (CNHS) is the first nationwide multi-ethnic cross-sectional interview and health examination conducted from 2012 to 2017. The survey is designed to study reference intervals for physiological constants as well as determinants of noncommunicable diseases among different ethnic populations in different areas, so that the data can be used to enhance clinical diagnosis strategies and health promotion. CNHS used a stratified, multistage cluster sampling method to obtain a sample of 53 895 people aged 20-80 years in 10 ethnic groups from 11 provinces or autonomous regions all over China. Blood samples were collected from each participant for the establishment of the China Multi-Ethnic Biobank (CMEB). CNHS collected data on demographic and socioeconomic information, lifestyle factors, anthropometric measures, laboratory tests and clinical profiles. These data provide a comprehensive resource for further study on risk factors of noncommunicable disease among different ethnic groups. Information about the CNHS database, including publication list, introduction of the survey design and methods, and guidelines for submitting electronic forms of data application, is available at [http://www.bmicc.cn/web/share/home].

    更新日期:2018-12-05
  • Past and current asbestos exposure and future mesothelioma risks in Britain: The Inhaled Particles Study (TIPS)
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-03-09
    Gilham C, Rake C, Hodgson J, et al.

    Background Occupational and environmental airborne asbestos concentrations are too low and variable for lifetime exposures to be estimated reliably, and building workers and occupants may suffer higher exposure when asbestos in older buildings is disturbed or removed. Mesothelioma risks from current asbestos exposures are therefore not known. Methods We interviewed and measured asbestos levels in lung samples from 257 patients treated for pneumothorax and 262 with resected lung cancer, recruited in England and Wales. Average lung burdens in British birth cohorts from 1940 to 1992 were estimated for asbestos-exposed workers and the general population. Results Regression analysis of British mesothelioma death rates and average lung burdens in birth cohorts born before 1965 suggests a lifetime mesothelioma risk of approximately 0.01% per fibre/mg of amphiboles in the lung. In those born since 1965, the average lung burden is ∼1 fibre/mg among those with no occupational exposure. Conclusions The average lifetime mesothelioma risk caused by recent environmental asbestos exposure in Britain will be about 1 in 10 000. The risk is an order of magnitude higher in a subgroup of exposed workers and probably in occupants in the most contaminated buildings. Further data are needed to discover whether asbestos still present in buildings, particularly schools, is a persistent or decreasing hazard to workers who disturb it and to the general population, and whether environmental exposure occurs predominantly in childhood or after beginning work. Similar studies are needed in other countries to estimate continuing environmental and occupational mesothelioma hazards worldwide, including the contribution from chrysotile.

    更新日期:2018-12-05
  • Is shift work associated with a higher risk of overweight or obesity? A systematic review of observational studies with meta-analysis
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-05-29
    Liu Q, Shi J, Duan P, et al.

    Background An increasing number of original studies suggest that exposure to shift work could be associated with the risk of overweight and obesity, but the results remain conflicted and inconclusive. This study aimed to quantitatively synthesize available epidemiological evidence on the association between shift work and the risk of overweight and obesity by a meta-analysis. Methods The authors searched PubMed, Embase and the reference lists of all included studies up to April 2017, with a verification search in December 2017. Inclusion criteria were original studies that reported odds ratios, relative risks or hazard ratios (ORs, RRs or HRs, respectively) of at least one outcome of overweight or obesity. Summary risk estimates were calculated by random-effect models. Results Twenty-six studies (7 cohort studies, 18 cross-sectional studies and 1 case–control study) involving 311 334 participants were identified. Among these studies, the cut-off points of overweight and obesity varied greatly, so the heterogeneity was substantial; however, the results were stable. Shift work was found to be positively associated with the risk of overweight [RR: 1.25; 95% confidence interval (95% CI): 1.08–1.44] and obesity (RR: 1.17; 95% CI: 1.12–1.22). Conclusions Individuals involved in shift work are more likely to become overweight or obese. Appropriate preventive interventions in the organization of shift schedules according to ergonomic criteria would allow shift workers to avoid potential health impairment.

    更新日期:2018-12-05
  • Circulating cotinine concentrations and lung cancer risk in the Lung Cancer Cohort Consortium (LC3)
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-06-12
    Larose T, Guida F, Fanidi A, et al.

    Background Self-reported smoking is the principal measure used to assess lung cancer risk in epidemiological studies. We evaluated if circulating cotinine—a nicotine metabolite and biomarker of recent tobacco exposure—provides additional information on lung cancer risk. Methods The study was conducted in the Lung Cancer Cohort Consortium (LC3) involving 20 prospective cohort studies. Pre-diagnostic serum cotinine concentrations were measured in one laboratory on 5364 lung cancer cases and 5364 individually matched controls. We used conditional logistic regression to evaluate the association between circulating cotinine and lung cancer, and assessed if cotinine provided additional risk-discriminative information compared with self-reported smoking (smoking status, smoking intensity, smoking duration), using receiver-operating characteristic (ROC) curve analysis. Results We observed a strong positive association between cotinine and lung cancer risk for current smokers [odds ratio (OR ) per 500 nmol/L increase in cotinine (OR500): 1.39, 95% confidence interval (CI): 1.32–1.47]. Cotinine concentrations consistent with active smoking (≥115 nmol/L) were common in former smokers (cases: 14.6%; controls: 9.2%) and rare in never smokers (cases: 2.7%; controls: 0.8%). Former and never smokers with cotinine concentrations indicative of active smoking (≥115 nmol/L) also showed increased lung cancer risk. For current smokers, the risk-discriminative performance of cotinine combined with self-reported smoking (AUCintegrated: 0.69, 95% CI: 0.68–0.71) yielded a small improvement over self-reported smoking alone (AUCsmoke: 0.66, 95% CI: 0.64–0.68) (P = 1.5x10–9). Conclusions Circulating cotinine concentrations are consistently associated with lung cancer risk for current smokers and provide additional risk-discriminative information compared with self-report smoking alone.

    更新日期:2018-12-05
  • Evaluating large-scale propensity score performance through real-world and synthetic data experiments
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-06-22
    Tian Y, Schuemie M, Suchard M.

    Background Propensity score adjustment is a popular approach for confounding control in observational studies. Reliable frameworks are needed to determine relative propensity score performance in large-scale studies, and to establish optimal propensity score model selection methods. Methods We detail a propensity score evaluation framework that includes synthetic and real-world data experiments. Our synthetic experimental design extends the ‘plasmode’ framework and simulates survival data under known effect sizes, and our real-world experiments use a set of negative control outcomes with presumed null effect sizes. In reproductions of two published cohort studies, we compare two propensity score estimation methods that contrast in their model selection approach: L1-regularized regression that conducts a penalized likelihood regression, and the ‘high-dimensional propensity score’ (hdPS) that employs a univariate covariate screen. We evaluate methods on a range of outcome-dependent and outcome-independent metrics. Results L1-regularization propensity score methods achieve superior model fit, covariate balance and negative control bias reduction compared with the hdPS. Simulation results are mixed and fluctuate with simulation parameters, revealing a limitation of simulation under the proportional hazards framework. Including regularization with the hdPS reduces commonly reported non-convergence issues but has little effect on propensity score performance. Conclusions L1-regularization incorporates all covariates simultaneously into the propensity score model and offers propensity score performance superior to the hdPS marginal screen.

    更新日期:2018-12-05
  • Susceptibility to price discounting of soda by neighbourhood educational status: an ecological analysis of disparities in soda consumption using point-of-purchase transaction data in Montreal, Canada
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-06-22
    Mamiya H, Moodie E, Ma Y, et al.

    Introduction Price discounting is a marketing tactic used frequently by food industries and retailers, but the extent to which education modifies the effect of discounting on the purchasing of unhealthy foods has received little attention. We investigated whether there was a differential association of price discounting of soda with store-level soda purchasing records between 2008 and 2013 by store-neighbourhood education in Montreal, Canada. Methods Using data on grocery purchase transactions from a sample of supermarkets, pharmacies, supercentres and convenience stores, we performed an ecological time-series analysis, modelling weekly store-level sales of soda as a function of store-level price discounting, store- and neighbourhood-level confounders and an interaction term between discounting and categorical education in the neighbourhood of each store. Results Analysis by store type (n = 18 743, 12 437, 3965 and 49 533 store-weeks for superstores, pharmacies, supercentres and convenience stores, respectively) revealed that the effect measure modification of discounting by neighbourhood education on soda purchasing was lower in stores in the more educated neighbourhoods, most notably in pharmacies: −0.020 [95% confidence interval (CI): −0.028, −0.012] and −0.038 (95% CI: −0.051, −0.025), for middle- and high-education categories, respectively). Weaker effect modification was observed in convenience stores. There was no evidence of effect modification in supercentres or superstores. Conclusions Price discounting is an important environmental risk factor for soda purchasing and can widen education inequalities in excess sugar intake across levels of education. Interventions to regulate price discounting warrant further investigation as a public health strategy to improve population nutrition, particularly in lower-education neighbourhoods.

    更新日期:2018-12-05
  • Errors in estimating usual sodium intake by the Kawasaki formula alter its relationship with mortality: implications for public health†
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-06-22
    He F, Campbell N, Ma Y, et al.

    Background Several cohort studies with inaccurate estimates of sodium reported a J-shaped relationship with mortality. We compared various estimated sodium intakes with that measured by the gold-standard method of multiple non-consecutive 24-h urine collections and assessed their relationship with mortality. Methods We analysed the Trials of Hypertension Prevention follow-up data. Sodium intake was assessed in four ways: (i) average measured (gold standard): mean of three to seven 24-h urinary sodium measurements during the trial periods; (ii) average estimated: mean of three to seven estimated 24-h urinary sodium excretions from sodium concentration of 24-h urine using the Kawasaki formula; (iii) first measured: 24-h urinary sodium measured at the beginning of each trial; (iv) first estimated: 24-h urinary sodium estimated from sodium concentration of the first 24-h urine using the Kawasaki formula. We included 2974 individuals aged 30–54 years with pre-hypertension, not assigned to sodium intervention. Results During a median follow-up of 24 years, 272 deaths occurred. The average sodium intake measured by the gold-standard method was 3769 ± 1282 mg/d. The average estimated sodium over-estimated the intake by 1297 mg/d (95% confidence interval: 1267–1326). The average estimated value was systematically biased with over-estimation at lower levels and under-estimation at higher levels. The average measured sodium showed a linear relationship with mortality. The average estimated sodium appeared to show a J-shaped relationship with mortality. The first measured and the first estimated sodium both flattened the relationship. Conclusions Accurately measured sodium intake showed a linear relationship with mortality. Inaccurately estimated sodium changed the relationship and could explain much of the paradoxical J-shaped findings reported in some cohort studies.

    更新日期:2018-12-05
  • Sodium intake and blood pressure in children and adolescents: a systematic review and meta-analysis of experimental and observational studies
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-06-27
    Leyvraz M, Chatelan A, da Costa B, et al.

    Background High sodium intake is a cause of elevated blood pressure in adults. In children and adolescents, less evidence is available and findings are equivocal. We systematically reviewed the evidence from experimental and observational studies on the association between sodium intake and blood pressure in children and adolescents. Methods A systematic search of the Medline, Embase, CINAHL and CENTRAL databases up to March 2017 was conducted and supplemented by a manual search of bibliographies and unpublished studies. Experimental and observational studies involving children or adolescents between 0 and 18 years of age were included. Random-effects meta-analyses were performed by pooling data across all studies, separately for experimental and observational studies, and restricting to studies with sodium intake and blood pressure measurement methods of high quality. Subgroup meta-analyses, sensitivity analyses and meta-regressions were conducted to investigate sources of heterogeneity and confounding. The dose–response relationship was also investigated. Results Of the 6572 publications identified, 85 studies (14 experimental; 71 observational, including 60 cross-sectional, 6 cohort and 5 case–control studies) with 58 531 participants were included. In experimental studies, sodium reduction interventions decreased systolic blood pressure by 0.6 mm Hg [95% confidence interval (CI): 0.5, 0.8] and diastolic blood pressure by 1.2 mm Hg (95% CI: 0.4, 1.9). The meta-analysis of 18 experimental and observational studies (including 3406 participants) with sodium intake and blood pressure measurement methods of high quality showed that, for every additional gram of sodium intake per day, systolic blood pressure increased by 0.8 mm Hg (95% CI: 0.4, 1.3) and diastolic blood pressure by 0.7 mm Hg (95% CI: 0.0, 1.4). The association was stronger among children with overweight and with low potassium intake. A quasi-linear relationship was found between sodium intake and blood pressure. Conclusions Sodium intake is positively associated with blood pressure in children and adolescents, with consistent findings in experimental and observational studies. Since blood pressure tracks across the life course, our findings support the reduction of sodium intake during childhood and adolescence to lower blood pressure and prevent the development of hypertension.

    更新日期:2018-12-05
  • Comparison of metabolite networks from four German population-based studies
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-07-02
    Iqbal K, Dietrich S, Wittenbecher C, et al.

    Background Metabolite networks are suggested to reflect biological pathways in health and disease. However, it is unknown whether such metabolite networks are reproducible across different populations. Therefore, the current study aimed to investigate similarity of metabolite networks in four German population-based studies. Methods One hundred serum metabolites were quantified in European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam (n = 2458), EPIC-Heidelberg (n = 812), KORA (Cooperative Health Research in the Augsburg Region) (n = 3029) and CARLA (Cardiovascular Disease, Living and Ageing in Halle) (n = 1427) with targeted metabolomics. In a cross-sectional analysis, Gaussian graphical models were used to construct similar networks of 100 edges each, based on partial correlations of these metabolites. The four metabolite networks of the top 100 edges were compared based on (i) common features, i.e. number of common edges, Pearson correlation (r) and hamming distance (h); and (ii) meta-analysis of the four networks. Results Among the four networks, 57 common edges and 66 common nodes (metabolites) were identified. Pairwise network comparisons showed moderate to high similarity (r = 63–0.96, h = 7–72), among the networks. Meta-analysis of the networks showed that, among the 100 edges and 89 nodes of the meta-analytic network, 57 edges and 66 metabolites were present in all the four networks, 58–76 edges and 75–89 nodes were present in at least three networks, and 63–84 edges and 76–87 edges were present in at least two networks. The meta-analytic network showed clear grouping of 10 sphingolipids, 8 lyso-phosphatidylcholines, 31 acyl-alkyl-phosphatidylcholines, 30 diacyl-phosphatidylcholines, 8 amino acids and 2 acylcarnitines. Conclusions We found structural similarity in metabolite networks from four large studies. Using a meta-analytic network, as a new approach for combining metabolite data from different studies, closely related metabolites could be identified, for some of which the biological relationships in metabolic pathways have been previously described. They are candidates for further investigation to explore their potential role in biological processes.

    更新日期:2018-12-05
  • The future burden of lung cancer attributable to current modifiable behaviours: a pooled study of seven Australian cohorts
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-07-02
    Laaksonen M, Canfell K, MacInnis R, et al.

    Background Knowledge of preventable disease and differences in disease burden can inform public health action to improve health and health equity. We quantified the future lung cancer burden preventable by behavioural modifications across Australia. Methods We pooled seven Australian cohort studies (n = 367 058) and linked them to national registries to identify lung cancers and deaths. We estimated population attributable fractions and their 95% confidence intervals (CIs) for modifiable risk factors, using risk estimates from the cohort data and risk factor exposure distribution from contemporary national health surveys. Results During the first 10-year follow-up, there were 2025 incident lung cancers and 20 349 deaths. Stopping current smoking could prevent 53.7% (95% CI, 50.0–57.2%) of lung cancers over 40 years and 18.3% (11.0–25.1%) in 10 years. The smoking-attributable burden is highest in males, those who smoke <20 cigarettes per day, are <75 years of age, unmarried, of lower educational attainment, live in remote areas or are healthy weight. Increasing physical activity and fruit consumption, if causal, could prevent 15.6% (6.9–23.4%) and 7.5% (1.3–13.3%) of the lung cancer burden, respectively. Jointly, the three behaviour modifications could prevent up to 63.0% (58.0–67.5%) of lung cancers in 40 years, and 31.2% (20.9–40.1%) or 43 300 cancers in 10 years. The preventable burden is highest among those with multiple risk factors. Conclusions Smoking remains responsible for the highest burden of lung cancer in Australia. The uneven burden distribution distinguishes subgroups that could benefit the most from activities to control the world’s deadliest cancer.

    更新日期:2018-12-05
  • The use of controls in interrupted time series studies of public health interventions
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-07-05
    Lopez Bernal J, Cummins S, Gasparrini A.

    Interrupted time series analysis differs from most other intervention study designs in that it involves a before-after comparison within a single population, rather than a comparison with a control group. This has the advantage that selection bias and confounding due to between-group differences are limited. However, the basic interrupted time series design cannot exclude confounding due to co-interventions or other events occurring around the time of the intervention. One approach to minimizse potential confounding from such simultaneous events is to add a control series so that there is both a before-after comparison and an intervention-control group comparison. A range of different types of controls can be used with interrupted time series designs, each of which has associated strengths and limitations. Researchers undertaking controlled interrupted time series studies should carefully consider a priori what confounding events may exist and whether different controls can exclude these or if they could introduce new sources of bias to the study. A prudent approach to the design, analysis and interpretation of controlled interrupted time series studies is required to ensure that valid information on the effectiveness of health interventions can be ascertained.

    更新日期:2018-12-05
  • Male-biased sex ratios in Australian migrant populations: a population-based study of 1 191 250 births 1999–2015
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-07-23
    Edvardsson K, Axmon A, Powell R, et al.

    Background The naturally occurring male-to-female (M/F) ratio at birth is 1.05. Higher ratios found primarily in countries across Asia have been attributed to prenatal sex selection due to son preference. There is growing evidence that sex-selective practices continue following migration; however, little is known about these practices following migration to Australia. Methods In this population-based study we assessed M/F ratios at birth per mother’s country of birth for all registered births 1999–2015 in Victoria, Australia (n = 1 191 250). We also compared the M/F ratio among births to mothers born elsewhere to that of mothers born in Australia, stratified by time period and parity. Results Compared with the naturally occurring M/F ratio as well as to the M/F ratio among births to mothers born in Australia, there was an increased ratio of male births to mothers born in India, China and South-East Asia, particularly at higher parities and in more recent time periods (elevated M/F ratios ranged from 1·079 to 1·248, relative risks of male birth ranged from 1·012 to 1·084 with confidence intervals between 1·001 and 1·160 and P-values between 0·005 and 0·039). The most male-biased sex ratios were found among multiple births to Indian-born mothers, and parity of two or more births to Indian and Chinese-born mothers in 2011–15. Conclusions The male-biased sex ratios observed in this study indicate that prenatal sex selection may be continuing following migration to Australia from countries where these practices have been documented. The excess of males among multiple births raises the question as to what role assisted reproduction plays. Findings also suggest that systematic discrimination against females starts in the womb.

    更新日期:2018-12-05
  • Cancer Epidemiology and Prevention
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-07-30
    Armstrong B.

    Schottenfeld and Fraumeni Cancer Epidemiology and Prevention. 4th edition. ThunMichael J, LinetMartha S, CerhanJames R, HaimanChristopher A and SchottenfeldDavid (eds). New York, NY: Oxford University Press, 2017, pp 1328, USD219.36, GBP165, ISBN: 9780190238667

    更新日期:2018-12-05
  • Cohort profile: The Boston Hospital Workers Health Study (BHWHS)
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-10
    Sabbath E, Hashimoto D, Boden L, et al.

    Profile in a nutshell The Boston Hospital Workers Health Study (BHWHS) is a longitudinal, integrated open cohort consisting of employer data and survey data on approximately 16 000 hospital-based patient care workers aged 18-72, based at two hospitals in Massachusetts, USA. It represents an employer-researcher intellectual partnership between Partners HealthCare, and the Harvard T.H. Chan Centre for Work, Health, and Wellbeing. Data include individual-level, employer-provided data on health care spending, workplace injury, staffing, human resources and workload, and survey data on a subset of workers (on working conditions, self-reported health conditions and health behaviours). Workers are grouped into work-groups or units, allowing multilevel in addition to longitudinal analyses. Although the data are restricted in how they can be distributed (although the team is open to collaboration from outside researchers), the BHWHS is a model of the public health benefits of data collaborations between researchers and employers. This cohort profile serves as a guide to other researcher-employer teams looking to establish a similar database and collaboration.

    更新日期:2018-12-05
  • AHR gene-dioxin interactions and birthweight in the Seveso Second Generation Health Study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-14
    Ames J, Warner M, Mocarelli P, et al.

    Background 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is proposed to interfere with fetal growth via altered activity of the aryl hydrocarbon receptor (protein: AHR; gene: AHR) pathway which regulates diverse biological and developmental processes including xenobiotic metabolism. Genetic variation in AHR is an important driver of susceptibility to low birthweight in children exposed to prenatal smoking, but less is known about these genetic interactions with TCDD, AHR’s most potent xenobiotic ligand. Methods The Seveso Women’s Health Study (SWHS), initiated in 1996, is a cohort of 981 Italian women exposed to TCDD from an industrial explosion in July 1976. We measured TCDD concentrations in maternal serum collected close to the time of the accident. In 2008 and 2014, we followed up the SWHS cohort and collected data on birth outcomes of SWHS women with post-accident pregnancies. We genotyped 19 single nucleotide polymorphisms (SNPs) in AHR among the 574 SWHS mothers. Results Among 901 singleton births, neither SNPs nor TCDD exposure alone were significantly associated with birthweight. However, we found six individual SNPs in AHR which adversely modified the association between maternal TCDD and birthweight, implicating gene-environment interaction. We saw an even stronger susceptibility to TCDD due to interaction when we examined the joint contribution of these SNPs in a risk allele score. These SNPs were all located in noncoding regions of AHR, particularly in proximity to the promoter. Conclusions This is the first study to demonstrate that genetic variation across the maternal AHR gene may shape fetal susceptibilities to TCDD exposure.

    更新日期:2018-12-05
  • Effects of ambient air pollution on incident Parkinson’s disease in Ontario, 2001 to 2013: a population-based cohort study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-16
    Shin S, Burnett R, Kwong J, et al.

    Background Despite recent studies linking air pollution to neurodegenerative illness, evidence relating air pollution and Parkinson’s disease (PD) remains scarce. We conducted a population-based cohort study in Ontario, Canada, to determine the association between air pollution and incident PD. Methods Using health administrative databases, we identified all adults aged 55–85 years, free of PD, and who lived in Ontario on 1 April 2001 (∼2.2 million). Individuals were followed up until 31 March 2013. We derived long-term average exposures to fine particulate matter (particles ≤2.5 µm in diameter, or PM2.5), nitrogen dioxide (NO2) and ozone from satellite-based estimates, land-use regression models and optimal interpolation methods, respectively. Using 2-year lags in exposures, we linked these estimates to individuals’ annual postal codes from 1994 (7 years before cohort inception). We applied spatial random-effects Cox proportional hazards models, adjusting for individual- and area-level characteristics. We also performed sensitivity analyses, such as considering longer lags in exposures and stratifying by selected characteristics. Results During the study period, we identified 38 745 newly diagnosed cases of PD. Each interquartile increment (3.8 µg/m3) of PM2.5 was associated with a 4% increase in incident PD (95% confidence interval, 1.01–1.08) after adjusting for various covariates. We also found positive associations for NO2 and ozone [hazard ratios (HRs) ranged from 1.03 to 1.04]. The associations for all exposures were unaltered with various sensitivity analyses except for considering longer lags, which somewhat attenuated the estimates, particularly for NO2 and ozone. Conclusions Exposure to air pollution, especially PM2.5, was found to be related to incident PD.

    更新日期:2018-12-05
  • Candidate genes linking maternal nutrient exposure to offspring health via DNA methylation: a review of existing evidence in humans with specific focus on one-carbon metabolism
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-17
    James P, Sajjadi S, Tomar A, et al.

    Background Mounting evidence suggests that nutritional exposures during pregnancy influence the fetal epigenome, and that these epigenetic changes can persist postnatally, with implications for disease risk across the life course. Methods We review human intergenerational studies using a three-part search strategy. Search 1 investigates associations between preconceptional or pregnancy nutritional exposures, focusing on one-carbon metabolism, and offspring DNA methylation. Search 2 considers associations between offspring DNA methylation at genes found in the first search and growth-related, cardiometabolic and cognitive outcomes. Search 3 isolates those studies explicitly linking maternal nutritional exposure to offspring phenotype via DNA methylation. Finally, we compile all candidate genes and regions of interest identified in the searches and describe their genomic locations, annotations and coverage on the Illumina Infinium Methylation beadchip arrays. Results We summarize findings from the 34 studies found in the first search, the 31 studies found in the second search and the eight studies found in the third search. We provide details of all regions of interest within 45 genes captured by this review. Conclusions Many studies have investigated imprinted genes as priority loci, but with the adoption of microarray-based platforms other candidate genes and gene classes are now emerging. Despite a wealth of information, the current literature is characterized by heterogeneous exposures and outcomes, and mostly comprise observational associations that are frequently underpowered. The synthesis of current knowledge provided by this review identifies research needs on the pathway to developing possible early life interventions to optimize lifelong health.

    更新日期:2018-12-05
  • Commentary: Asbestos exposure and mesothelioma risk
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-17
    Krupoves A.

    Exposure to asbestos is the cause of the most important occupational disease epidemic of the 20th century, and it remains highly relevant to public health even after asbestos has largely disappeared from manufacture and from new uses in many countries.1 There are still 125 million people exposed to asbestos in the workplace, according to the World Health Organization.2 In addition, most of the asbestos that was ever used is still in place and is therefore a potential source of exposure for workers in renovation, demolition, maintenance and waste removal.

    更新日期:2018-12-05
  • Relationship of genetic determinants of height with cardiometabolic and pulmonary traits in the Hispanic Community Health Study/Study of Latinos
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-21
    Sofer T, Moon J, Isasi C, et al.

    Background Associations of adult height with cardiometabolic and pulmonary traits have been studied in majority European ancestry populations using Mendelian randomization and polygenic risk score (PRS) analysis. The standard PRS approach entails creating a PRS for height using variants identified in prior genome-wide association studies (GWAS). It is unclear how well the standard PRS approach performs in non-European populations and whether height–trait associations observed in Europeans are also observed in other populations. Methods In the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), we used: (i) the standard approach to create a PRS for height (PRS1) and (ii) a novel approach to optimize the selection of variants from previously established height association loci to better explain height in HCHS/SOL (PRS2). We also estimated the extent to which PRS–trait associations were independent or mediated by the PRS effect on height. Results In 7539 women and 5245 men, PRS1 and PRS2 explained 9 and 29% of the variance in measured height, respectively. Both PRS1 and PRS2 were associated with forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/ FVC ratio, total cholesterol and 2-hour oral glucose-tolerance test insulin levels. Additionally, PRS2 was associated with estimated glomerular filtration rate and ankle brachial index. Both PRS1 and PRS2 had pleiotropic associations with FEV1/ FVC ratio in mediation analyses. Conclusions Associations of polygenic scores of height with measures of lung function and cholesterol were consistent with those observed in prior studies of majority European ancestry populations. Mediation analysis may augment standard PRS approaches to disentangle pleiotropic and mediated effects.

    更新日期:2018-12-05
  • Commentary: Past and current asbestos exposure and future mesothelioma risks in Britain
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-28
    Terracini B.

    The recent paper by Gilham et al.1 quantifies the effectiveness of the asbestos regulations implemented in the UK in 1969 and which were followed shortly afterwards by the abandonment of the use of crocidolite and, more than 15 years later, by an official ban on crocidolite and amosite in that country. Both the reduction in mesothelioma incidence and mortality up to age 50 and the fall in the amphibole burden in the lungs in a representative sample of the British population are impressive. Had other countries adopted similar regulations 50 years ago, many asbestos-related deaths would have been avoided worldwide. For instance, this is significant for Italy, where the lack of adequate preventive measures (at the time) led to a delay of more than a decade in the decline in asbestos consumption compared with the UK.2

    更新日期:2018-12-05
  • Green tea consumption and risk of type 2 diabetes in Chinese adults: the Shanghai Women’s Health Study and the Shanghai Men’s Health Study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-29
    Liu X, Xu W, Cai H, et al.

    Background Epidemiological evidence on the association between tea consumption and the risk of type 2 diabetes (T2D) is inconsistent. This study prospectively investigated whether green tea drinking affects the risk of T2D. Methods This study included participants from the Shanghai Women’s Health Study (N = 67 058) and the Shanghai Men’s Health Study (N = 52 315) without diabetes at study enrolment. Details of tea consumption, including types and amounts, were collected at the baseline and follow-up survey. Incident T2D was identified through follow-up surveys. Plasma level of caffeine metabolite was measured in a nested case-control study involving 592 diabetes case-control pairs. Cox regression analysis, with tea drinking as a time-dependent variable and covariates adjusted for by a propensity score, was applied to estimate the hazard ratio (HR) and 95% confidence interval (CI) for T2D risk. Logistic regression analysis was applied to evaluate the association between caffeine metabolites and T2D risk. Results Current green tea drinkers had an increased risk of T2D compared with non-current drinkers [HR = 1.20 (95% CI = 1.14–1.27)], and a dose-response relationship was observed for duration of drinking tea and the amount of tea consumed [P for trend <0.001]. The increased risk associated with green tea drinking was observed in both women and men, across the entire period of follow-up, with HR (95% CI) of 1.08 (0.97–1.19) within 5 years of follow-up, 1.22 (1.12–1.32) during the period of 5–10 years of follow-up and 1.16 (1.03–1.30) after 10 years of follow-up. This association did not vary significantly by body mass index, waist-to-hip circumference ratio or smoking status. Plasma level of caffeine was also associated with increased diabetes risk (P = 0.03), confirming the results based on self-reported tea drinking. Conclusions Green tea drinking was associated with an increased risk of T2D in Chinese adults. The mechanisms underlying the association need to be elucidated.

    更新日期:2018-12-05
  • Osteoarthritis and risk of mortality in the USA: a population-based cohort study
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-08-29
    Mendy A, Park J, Vieira E.

    Background Osteoarthritis (OA) is the most common joint disease, but its association with mortality is unclear. Methods We analysed data on adult participants in the 1988–94 and 1999–2010 National Health and Nutrition Examination Surveys, followed for mortality through 2011. OA was defined by self-report, and in a subset of participants 60 years or older with knee X-rays, radiographic knee OA (RKOA) was defined as Kellgren–Lawrence score ≥2. Cox proportional hazards were used to determine the mortality hazard ratio (HR) associated with self-reported OA and RKOA, adjusting for covariates. Results The sample included 51 938 participants followed for a median 8.9 years; 2589 of them had knee X-rays and were followed for a median of 13.6 years. Self-reported OA and RKOA prevalences were 6.6% and 40.6%, respectively. Self-reported OA was not associated with mortality. RKOA was associated with an increased risk of mortality from cardiovascular diseases (CVD) {HR 1.43 [95% confidence interval (CI): 1.32, 1.64]}, diabetes [HR 2.04 (1.87, 2.23)] and renal diseases [HR 1.14 (1.04, 1.25)], but with a reduced risk of cancer mortality [HR 0.88 (0.80, 0.96)]. Participants with early RKOA onset (diagnosed before age 40) had a higher risk of mortality from all causes [HR 1.53 (1.43, 1.65)] and from diabetes [HR 7.18 (5.45, 9.45)]. Obese participants with RKOA were at increased risk of mortality from CVD [HR 1.89 (1.56, 2.29)] and from diabetes [HR: 3.42 (3.01, 3.88)]. Conclusions Self-reported OA was not associated with mortality. RKOA was associated with higher CVD, diabetes and renal mortality, especially in people with early onset of the disease or with obesity.

    更新日期:2018-12-05
  • Evaluating temporal patterns of snakebite in Sri Lanka: the potential for higher snakebite burdens with climate change
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-09-11
    Ediriweera D, Diggle P, Kasturiratne A, et al.

    Background Snakebite is a neglected tropical disease that has been overlooked by healthcare decision makers in many countries. Previous studies have reported seasonal variation in hospital admission rates due to snakebites in endemic countries including Sri Lanka, but seasonal patterns have not been investigated in detail. Methods A national community-based survey was conducted during the period of August 2012 to June 2013. The survey used a multistage cluster design, sampled 165 665 individuals living in 44 136 households and recorded all recalled snakebite events that had occurred during the preceding year. Log-linear models were fitted to describe the expected number of snakebites occurring in each month, taking into account seasonal trends and weather conditions, and addressing the effects of variation in survey effort during the study and of recall bias amongst survey respondents. Results Snakebite events showed a clear seasonal variation. Typically, snakebite incidence is highest during November–December followed by March–May and August, but this can vary between years due to variations in relative humidity, which is also a risk factor. Low relative-humidity levels are associated with high snakebite incidence. If current climate-change projections are correct, this could lead to an increase in the annual snakebite burden of 31.3% (95% confidence interval: 10.7–55.7) during the next 25–50 years. Conclusions Snakebite in Sri Lanka shows seasonal variation. Additionally, more snakebites can be expected during periods of lower-than-expected humidity. Global climate change is likely to increase the incidence of snakebite in Sri Lanka.

    更新日期:2018-12-05
  • Long-term consumption of fruits and vegetables and risk of chronic obstructive pulmonary disease: a prospective cohort study of women
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-09-18
    Kaluza J, Harris H, Linden A, et al.

    Background Fruits and vegetables, due to high antioxidant capacity, may protect the lung from oxidative damage caused by tobacco smoke and potentially prevent chronic obstructive pulmonary disease (COPD). Only one study based on baseline diet has examined fruit and vegetable consumption in relation to risk of COPD, and no previous studies have examined long-term diet. Methods We investigated whether long-term fruit and vegetable consumption was associated with COPD incidence among 34 739 women (age 48–83 years) in the population-based prospective Swedish Mammography Cohort. Fruit and vegetable consumption was assessed twice (1987, 1997) with a self-administered questionnaire. Cases of COPD were identified by linkage to the Swedish health register. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results During follow-up from 2002 to 2014, 1512 women were diagnosed with COPD. Long-term fruit was associated with lower risk of COPD; women in the highest vs lowest quintile of consumption (≥2.5 vs <0.8 servings/day) had a 37% lower risk of COPD (95% CI: 25–48%; P-trend < 0.0001). No association was observed with long-term vegetable intake. Current and ex-smokers with low long-term consumption of fruits (<1 serving/day) in comparison to never smokers with high consumption (≥3 servings/day) had a 38-fold (HR: 38.1; 95% CI: 20.2–71.7) and 13-fold (HR: 12.5, 95% CI: 6.5–24.1) higher risk of COPD, respectively. However, no significant interaction between smoking status and fruit intake in relation to COPD incidence was observed (P-interaction = 0.95). Conclusions In this prospective cohort of middle-age and older women, long-term consumption of fruits but not vegetables was inversely associated with COPD incidence.

    更新日期:2018-12-05
  • Global prevalence of percutaneous injuries among healthcare workers: a systematic review and meta-analysis
    Int. J. Epidemiol. (IF 8.36) Pub Date : 2018-09-28
    Auta A, Adewuyi E, Tor-Anyiin A, et al.

    Background Healthcare workers (HCWs) are at risk of occupational exposure to blood-borne pathogens through contact with human blood and other body fluids. This study was conducted to estimate the global and regional 1-year prevalence of percutaneous injuries (PCIs) among HCWs. Methods We systematically searched EMBASE, PubMed, CINAHL and PsychInfo databases for studies published from January 2008 to January 2018 that reported the prevalence of PCIs among HCWs. A random-effects meta-analysis was conducted to estimate pooled prevalence of PCIs among HCWs. Results Of the 5205 articles identified, 148 studies from 43 countries met the inclusion criteria. The pooled global 1-year prevalence estimate of PCIs was 36.4% [95% confidence interval (CI): 32.9–40.0]. There were substantial regional variations in the 1-year prevalence of PCIs, ranging from 7.7% (95% CI: 3.1–12.4) in South America to 43.2% (95% CI: 38.3–48.0) in Asia. The estimates for Africa and Europe were comparable with values of 34.5% (95% CI: 29.9–39.1) and 31.8% (95% CI: 25.0–38.5), respectively. The highest 1-year prevalence by job category was among surgeons, at 72.6% (95% CI: 58.0–87.2). The estimates for medical doctors (excluding surgeons), nurses (including midwives) and laboratory staff (including laboratory technicians) were 44.5% (95% CI: 37.5–51.5), 40.9% (95% CI: 35.2–46.7) and 32.4% (95% CI: 20.9–49.3), respectively. PCIs commonly occurred among HCWs working in hospital (41.8%, 95% CI: 37.6–46.0) than non-hospital (7.5%, 95% CI: 5.9–9.1) settings. Conclusions Our findings suggest high rates of PCIs among HCWs with direct patient care across many regions of the world. However, paucity of data from some countries was a major limitation.

    更新日期:2018-12-05
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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