van de Mheen P J, Gunning-Schepers L J
Institute of Social Medicine, University of Amsterdam, The Netherlands.
Am J Epidemiol. 1994 Jul 1;140(1):52-7. doi: 10.1093/oxfordjournals.aje.a117158.
The purpose of this study was to determine whether the reported increase in the percentage of never smokers in the group of men born between 1924 and 1938, as observed in survey data in the Netherlands, can be attributed to differential mortality or to misclassification. In a spreadsheet program, the mortality experiences of the men born in 1924 and 1938 were simulated with the use of lifetable techniques. Due to differential mortality, the percentage of true never smokers would be expected to increase from 9% to 9.3% for men born in 1938 and from 9% to 10.3% for men born in 1924. In the survey, the percentage of people who reported that they had never smoked increased from 9% to 36% for the men born between 1924 and 1938. Differential mortality can only explain a very small part of the reported increase in the percentage of "never" smokers. Misclassification of former smokers as never smokers is the most likely cause for the reported increase. This is reason for concern, because even a small percentage of misclassified former smokers may bias the estimated relative risk of mortality associated with current smoking to a considerable extent. Because former smoking status cannot be measured correctly, the percentage of former smokers may be calculated by modeling the percentage of ever smokers.
本研究的目的是确定在荷兰调查数据中观察到的1924年至1938年出生男性中从不吸烟者比例的报告增加，是可归因于不同的死亡率还是错误分类。在一个电子表格程序中，利用生命表技术模拟了1924年和1938年出生男性的死亡经历。由于不同的死亡率，预计1938年出生男性中真正从不吸烟者的比例将从9%增至9.3%，1924年出生男性中这一比例将从9%增至10.3%。在该调查中，1924年至1938年出生男性中报告从不吸烟的人的比例从9%增至36%。不同的死亡率只能解释报告的“从不”吸烟者比例增加的很小一部分。将曾经吸烟者错误分类为从不吸烟者是报告增加的最可能原因。这令人担忧，因为即使是一小部分被错误分类的曾经吸烟者也可能在很大程度上使与当前吸烟相关的死亡率估计相对风险产生偏差。由于无法正确测量曾经吸烟状态，曾经吸烟者的比例可通过对曾经吸烟人群的比例进行建模来计算。
