Duffy S W, Maximovitch D M, Day N E
Medical Research Council Biostatistics Unit, Institute of Public Health, Cambridge, United Kingdom.
J Epidemiol Community Health. 1992 Dec;46(6):620-4. doi: 10.1136/jech.46.6.620.
The aim was to quantify the difference in precision of risk estimates in epidemiology between the situations where misclassification of exposure is corrected for by external validation and where it is corrected for by internal repeat measurement. Precision was measured in terms of the expected width of the 95% confidence interval on the odds ratio.
In a hypothetical case-control study, first with 100 cases and 100 controls, then with 100 cases and 1000 controls (the latter to approximate the cohort study situation), expected estimated odds ratios and confidence intervals were calculated based on postulated underlying true odds ratios and misclassification error rates. The sizes of the confidence intervals using the two design strategies were compared, based on the same number of subjects receiving internal repeat measurements as were used in the external validation study.
Confidence intervals obtained using internal repeat measurement were considerably narrower than those using external validation. Both methods yielded approximately correct point estimates.
In terms of precision, it is preferable to correct for misclassification using internal repeat measurement rather than external validation.
目的是量化在流行病学中，通过外部验证校正暴露误分类的情况与通过内部重复测量校正暴露误分类的情况之间，风险估计精度的差异。精度通过比值比的95%置信区间的预期宽度来衡量。
在一项假设的病例对照研究中，首先有100例病例和100名对照，然后有100例病例和1000名对照（后者近似队列研究情况），根据假定的潜在真实比值比和误分类错误率计算预期估计比值比和置信区间。基于与外部验证研究中接受内部重复测量的受试者数量相同的受试者数量，比较使用两种设计策略得到的置信区间大小。
使用内部重复测量获得的置信区间比使用外部验证获得的置信区间窄得多。两种方法都产生了大致正确的点估计。
在精度方面，使用内部重复测量校正误分类比使用外部验证更可取。
