Liang K Y, Hanfelt J
Department of Biostatistics, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, Maryland 21205.
Biometrics. 1994 Sep;50(3):872-80.
This paper concerns the impact of litter effects on the inference of dose-response relationships in teratological experiments with binary response. Kupper et al. (1986, Biometrics 42, 85-98) concluded that when intra-litter correlations are dose-dependent, the use of a common intra-litter correlation likelihood based on the beta-binomial distribution could lead to severe bias in estimation of the parameter beta, which characterizes the dose-response relationship. We show here that the problems of bias and coverage probability for beta could still be substantial when one uses the likelihood with heterogeneous intra-litter correlations. We then examine through a simulation study the performance of the quasi-likelihood method (Wedderburn, 1974, Biometrika 61, 439-447) and recommend that this method with a common intra-litter correlation parameter be used when the number of litters is small or modest.
本文关注在具有二元反应的致畸实验中，窝效应（litter effects）对剂量反应关系推断的影响。库珀等人（1986年，《生物统计学》42卷，85 - 98页）得出结论，当窝内相关性与剂量相关时，基于贝塔二项分布使用共同的窝内相关性似然函数可能会导致在表征剂量反应关系的参数β估计中出现严重偏差。我们在此表明，当使用具有异质窝内相关性的似然函数时，β的偏差和覆盖概率问题可能仍然很大。然后，我们通过模拟研究检验了拟似然方法（韦德伯恩，1974年，《生物统计学杂志》61卷，439 - 447页）的性能，并建议在窝数较少或适中时使用具有共同窝内相关参数的该方法。
