Nam J M, Fears T R
Biostatistics Branch, National Cancer Institute, Rockville, Maryland 20892.
Stat Med. 1990 Dec;9(12):1475-83. doi: 10.1002/sim.4780091211.
We investigate the allocation of samples over strata in case-control studies with consideration of sampling costs. We consider two situations, typical of strata-matched case-control studies. Subject to a fixed total cost we derived optimum allocations that maximize the asymptotic efficiency of Cochran's test, that is, minimize the variance of the maximum likelihood estimator of the common odds ratio when the common odds ratio is one. Our results show that the standard design with equal numbers of cases and controls in each stratum is inefficient when costs per control differ greatly from stratum to stratum. We show that the optimum design suggested in this paper is robust for values of the odds ratio common in epidemiologic studies.
我们在考虑抽样成本的情况下，研究病例对照研究中样本在各层的分配情况。我们考虑了两种典型的分层匹配病例对照研究情况。在总成本固定的情况下，我们推导出了最优分配方案，该方案能使 Cochr an检验的渐近效率最大化，即当共同比值比为1时，使共同比值比的最大似然估计量的方差最小。我们的结果表明，当各层每个对照的成本差异很大时，每层病例和对照数量相等的标准设计效率低下。我们表明，本文提出的最优设计对于流行病学研究中常见的比值比取值具有稳健性。
