Maguire M G, Tonascia J, Sartwell P E, Stolley P D, Tockman M S
Am J Epidemiol. 1979 Aug;110(2):188-95. doi: 10.1093/oxfordjournals.aje.a112803.
In a previously reported case-control study of the relationship between oral contraceptives and thromboembolism, there were 461 cases and 1302 controls, individually matched on age, race, marital status, hospital, and date of admission. Initially, the control patients had not been matched with the cases for the presence or absence of six factors thought to predispose to or precipitate thromboembolic disease. The present paper reports the effects of taking into consideration these factors in the controls. Two methods of analysis (matched set, and logistic regression) gave closely similar results. Where the case series consisted of idiopathic cases, the revised estimate of the relative risk was reduced from 7.2 to 4.7 by these procedures; for predisposed cases, it was increased from 1.2 to 2.2. The explanation suggested in the previous report for the failure to find an increased risk for cases with predisposition receives support from these findings. Variation in the relative risk was examined for four separate diagnostic categories: venous thrombosis alone, pulmonary embolism alone, venous thrombosis and pulmonary embolism together, and myocardial infarction. The relative risk estimates were greater than unity for each thrombosis category for both predisposed and non-predisposed cases. The relative risk was not found to vary significantly according to age or smoking status.
在先前报道的一项关于口服避孕药与血栓栓塞关系的病例对照研究中，有461例病例和1302例对照，根据年龄、种族、婚姻状况、医院和入院日期进行个体匹配。最初，对照患者未根据六种被认为易患或促发血栓栓塞性疾病的因素的有无与病例进行匹配。本文报告了在对照中考虑这些因素的影响。两种分析方法（匹配集和逻辑回归）得出了非常相似的结果。在病例系列由特发性病例组成的情况下，通过这些程序，相对风险的修订估计值从7.2降至4.7；对于易感病例，相对风险从1.2增至2.2。先前报告中对易感病例未发现风险增加的解释从这些发现中得到了支持。对四个单独的诊断类别（单独的静脉血栓形成、单独的肺栓塞、静脉血栓形成和肺栓塞同时存在、心肌梗死）的相对风险变化进行了检查。对于易感和非易感病例，每个血栓形成类别的相对风险估计值均大于1。未发现相对风险根据年龄或吸烟状况有显著差异。
