Greenland S
Stat Med. 1984 Apr-Jun;3(2):131-41. doi: 10.1002/sim.4780030206.
This paper examines several methods for deriving standardized morbidity ratios (SMR) and attributable fraction (attributable risk percentage) estimates. We show that some of the proposed methods will, in general, produce biased estimators, although the low variance of certain estimators sometimes compensates for their bias. A few methods are based on statistical fallacies and should be avoided, especially the method of deriving the expected number of cases from a regression equation that does not include the exposure under study.
本文研究了几种推导标准化发病比（SMR）和归因分数（归因风险百分比）估计值的方法。我们表明，一般来说，一些提议的方法会产生有偏差的估计量，尽管某些估计量的低方差有时会弥补其偏差。有几种方法基于统计谬误，应该避免使用，特别是那种从一个不包含所研究暴露因素的回归方程中推导预期病例数的方法。
