OBJECTIVES The association of current smoking with influenza infection is not widely recognised. The aim of this systematic review was to summarise published evidence and quantify the risk of influenza infection in tobacco smokers compared to non-smokers. METHODS We systematically searched MEDLINE, EMBASE, CINAHL, LILACS and Web of Science, from inception to 7 November 2017, to identify relevant randomised control trials, cohort and case-control studies. Study quality was assessed using the Newcastle-Ottawa Scale. We included studies defining influenza as a clinical syndrome and those using confirmatory microbiological tests. Pooled odds ratios (ORs) were estimated by using random effects model. RESULTS The mean quality score across the nine included studies (n = 40,685 participants) was 5.4 of 9 (SD 1.07). Current smokers were over 5 times more likely to develop laboratory-confirmed influenza than non-smokers (pooled OR 5.69 (95% CI 2.79-11.60), 3 studies). For studies reporting the occurrence of an influenza-like illness (ILI), current smokers were 34% more likely to develop ILI than non-smokers (pooled OR 1.34 (95% CI 1.13-1.59), 6 studies). CONCLUSION Current smokers have an increased risk of developing influenza compared to non-smokers. The association was strongest in studies examining cases with laboratory confirmed influenza.

中文翻译：

---

吸烟与流行性感冒的发生-系统评价。

目的当前吸烟与流感感染之间的关联尚未得到广泛认可。本系统综述的目的是总结已发表的证据，并对与非吸烟者相比吸烟者中流感感染的风险进行量化。方法从开始到2017年11月7日，我们系统地搜索了MEDLINE，EMBASE，CINAHL，LILACS和Web of Science，以确定相关的随机对照试验，队列研究和病例对照研究。研究质量使用纽卡斯尔-渥太华量表进行评估。我们纳入了将流行性感冒定义为临床综合征的研究，以及使用确认性微生物学检验的研究。通过使用随机效应模型估计合并的优势比（OR）。结果纳入的9项研究（n = 40,685名参与者）的平均质量得分为5.4（共9）（SD 1.07）。目前的吸烟者发生实验室确诊流感的可能性是非吸烟者的5倍以上（合并OR为5.69（95％CI 2.79-11.60），3个研究）。对于报告发生类似流感的疾病（ILI）的研究，目前的吸烟者比非吸烟者罹患ILI的可能性高34％（合并OR 1.34（95％CI 1.13-1.59），6个研究）。结论与不吸烟者相比，目前的吸烟者患流感的风险增加。该协会在检查实验室确诊的流感病例的研究中最强。结论与不吸烟者相比，目前的吸烟者患流感的风险增加。该协会在检查实验室确诊的流感病例的研究中最强。结论与不吸烟者相比，目前的吸烟者患流感的风险增加。该协会在检查实验室确诊的流感病例的研究中最强。