Radon Katja, Goldberg Mark, Becklake Margaret
Department of Medicine, Joint Departments of Epidemiology and Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada.
Scand J Work Environ Health. 2002 Oct;28(5):328-32. doi: 10.5271/sjweh.682.
Despite the recognition of selection biases arising from the healthy worker effect in occupational mortality studies, the possibility of similar effects in occupational cohort studies on respiratory symptoms is not well known. Two mechanisms are responsible for the healthy worker effect in respiratory cohort studies. One is health-based selection of workers into employment (healthy him effect), and the other is health-based differential losses to follow-up (healthy worker survivor effect). The aim of the present paper was to estimate the magnitude of the healthy worker survivor effect in cohort studies of symptoms of chronic bronchitis.
A meta-analysis of occupational cohort studies of symptoms of chronic bronchitis was performed that included published articles identified in searches of the Medline bibliographic databases between 1980 and March 2001 and the reference lists of the located articles.
Eight cohort studies were identified using an a priori selection criterion. The pooled odds ratio of the prevalence of chronic bronchitis for subjects leaving the cohorts was 1.23 when these subjects were compared with those who remained under study (95% confidence interval 1.04-1A4).
The prevalence of respiratory symptoms among exposed workers may he underestimated if the healthy worker survivor effect is not taken into account
尽管在职业死亡率研究中已认识到健康工人效应所产生的选择偏倚，但职业队列研究中类似效应在呼吸症状方面的可能性却鲜为人知。在呼吸队列研究中，健康工人效应由两种机制导致。一种是基于健康状况的工人就业选择（健康入职效应），另一种是基于健康状况的随访差异失访（健康工人幸存者效应）。本文旨在估计慢性支气管炎症状队列研究中健康工人幸存者效应的程度。
对慢性支气管炎症状的职业队列研究进行荟萃分析，纳入1980年至2001年3月期间在Medline书目数据库检索中识别出的已发表文章以及所找到文章的参考文献列表。
使用预先设定的选择标准识别出八项队列研究。与仍在研究中的受试者相比，离开队列的受试者慢性支气管炎患病率的合并比值比为1.23（95%置信区间1.04 - 1.4）。
如果不考虑健康工人幸存者效应，暴露工人中呼吸症状的患病率可能被低估。
