Existing studies on multimorbidity have largely excluded oral diseases in multimorbidity prevalence estimates. The reason behind this is somewhat unclear, as chronic oral conditions are highly prevalent, affecting over half the global population. To address this gap, we examined the relationship between social disadvantage and multimorbidity, stratifying by the inclusion and exclusion of oral conditions. For participants aged 30 y and over ( n = 3,693), cross-sectional analysis was carried out using the US National Health and Nutrition Survey (2013–2014). Multimorbidity was defined as having 2 or more chronic conditions. Five medical conditions were examined: diabetes, asthma, arthritis, cardiovascular disease, and depression, as well as 4 oral health conditions: caries, periodontal disease, number of teeth, and edentulousness. Education and income poverty ratio were selected as measures of social disadvantage. Multimorbidity prevalence estimates according to social disadvantage were analyzed on an absolute and relative scale using inverse probability treatment weighting (IPTW), adjusting for age, sex, and ethnicity. The inclusion of oral health conditions in the assessment of multimorbidity increased the overall prevalence of multimorbidity from 20.8% to 53.4%. Findings from IPTW analysis demonstrated clear social gradients for multimorbidity estimates stratified by the exclusion of oral conditions. Upon inclusion of oral conditions, the prevalence of multimorbidity was higher across all social groups for both education and income. Stratifying by the inclusion of oral conditions, the mean probability of multimorbidity was 27% (95% confidence interval [CI], 23%–30%) higher in the low-education group compared to the high-education group. Similarly, the mean probability of multimorbidity was 44% (95% CI, 40%–48%) higher in the low-income group. On a relative scale, low education was associated with a 1.52 times (95% CI, 1.44–1.61) higher prevalence of multimorbidity compared to high education. Low income was associated with a 2.18 (95% CI, 1.99–2.39) higher prevalence of multimorbidity. This novel study strongly supports the impact of chronic oral conditions on multimorbidity prevalence estimates.

中文翻译：

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美国的社会劣势和包括口腔疾病在内的多种疾病

现有的多发病研究在多发病患病率估计中很大程度上排除了口腔疾病。其背后的原因尚不清楚，因为慢性口腔疾病非常普遍，影响着全球一半以上的人口。为了解决这一差距，我们研究了社会劣势与多重发病之间的关系，通过纳入和排除口腔疾病进行分层。对于 30 岁及以上的参与者（n = 3,693），利用美国国家健康和营养调查（2013-2014）进行横断面分析。多重发病被定义为患有两种或多种慢性病。检查了五种医疗状况：糖尿病、哮喘、关节炎、心血管疾病和抑郁症，以及四种口腔健康状况：龋齿、牙周病、牙齿数量和无牙颌。选择教育和收入贫困率作为社会劣势的衡量标准。使用逆概率治疗权重（IPTW），对年龄、性别和种族进行调整，在绝对和相对范围内分析根据社会劣势的多种发病率估计值。将口腔健康状况纳入多重疾病评估后，多重疾病的总体患病率从 20.8% 增加至 53.4%。 IPTW 分析的结果表明，通过排除口腔疾病，对多种发病率的估计存在明显的社会梯度。纳入口腔疾病后，所有社会群体的受教育程度和收入水平的多重发病率均较高。通过纳入口腔疾病进行分层，与高教育组相比，低教育组的多发病平均概率高 27%（95% 置信区间 [CI]，23%–30%）。同样，低收入组的多发病平均概率高出 44%（95% CI，40%–48%）。相对而言，与高教育程度相比，低教育程度与高 1.52 倍（95% CI，1.44-1.61）的多种疾病患病率相关。低收入与多病患病率升高 2.18（95% CI，1.99–2.39）相关。这项新颖的研究有力地支持了慢性口腔疾病对多种疾病患病率估计的影响。