Steenland K, Beaumont J, Halperin W
Scand J Work Environ Health. 1984 Jun;10(3):143-9. doi: 10.5271/sjweh.2349.
Cohort mortality studies, which compare the observed mortality of a historically exposed cohort to an expected mortality based on figures from a national population, are among the most common and useful types of studies done in occupational epidemiology. Such studies are primarily based on records which lack data on smoking. Hence it is often difficult to determine whether an observed excess of a given smoking-related disease is the result of occupational exposures, an excess consumption of cigarettes among the exposed, or an interaction between the two. The purpose of this paper is to outline the different types of control which may be exercised in cohort mortality studies to control for the effects of smoking. Indirect control, which uses only existing data, may be exercised through (i) analysis of other smoking-related causes of death besides the cause-of-death of primary interest, (ii) use of an internal reference group instead of the national population, (iii) adjustment of the excess risk based on hypothetical smoking habits, or (iv) analysis for a dose-response relationship between occupational exposure and disease. Direct control, which requires interviews, may be exercised through (i) a survey of the smoking habits of currently employed cohort members, (ii) a survey of all cohort members, or (iii) a "nested" case-referent study within the cohort. The choice of which method to use depends on the cost and the degree of accuracy required by the investigator.
队列死亡率研究是职业流行病学中最常见且有用的研究类型之一，该研究将历史暴露队列的观察死亡率与基于全国人口数据的预期死亡率进行比较。此类研究主要基于缺乏吸烟数据的记录。因此，通常很难确定观察到的特定吸烟相关疾病的超额发生率是职业暴露、暴露人群中香烟消费量过多还是两者相互作用的结果。本文的目的是概述在队列死亡率研究中可用于控制吸烟影响的不同类型的对照方法。仅使用现有数据的间接对照可通过以下方式进行：（i）分析除主要关注的死因之外的其他吸烟相关死因；（ii）使用内部参照组而非全国人口；（iii）根据假设的吸烟习惯调整超额风险；或（iv）分析职业暴露与疾病之间的剂量反应关系。需要访谈的直接对照可通过以下方式进行：（i）对当前在职队列成员的吸烟习惯进行调查；（ii）对所有队列成员进行调查；或（iii）在队列中进行“嵌套”病例对照研究。使用哪种方法的选择取决于研究者所需的成本和准确度。
