A mixture of a distribution of responses from untreated patients and a shift of that distribution is a useful model for the responses from a group of treated patients. The mixture model accounts for the fact that not all the patients in the treated group will respond to the treatment and consequently their responses follow the same distribution as the responses from untreated patients. The treatment effect in this context consists of both the fraction of the treated patients that are responders and the magnitude of the shift in the distribution for the responders. In this paper, we investigate properties of the method of moment estimators for the treatment effect and demonstrate their usefulness for obtaining approximate confidence intervals without any parametric assumptions about the distribution of responses.
翻译:混合分发未经治疗的病人的答复和转移分发,是一组经治疗的病人的答复的有益模式,混合物模型说明,并非所有受治疗组的病人都对治疗作出反应,因此,他们的答复同未经治疗的病人的答复一样分布,这一背景下的治疗效果包括作为反应者接受治疗的病人的一小部分,以及反应者分发情况的变化程度。我们在本文件中调查对治疗效果进行即时估测的方法的特性,并表明它们对于获得大致的信任间隔是有用的,对反应的分布不作任何参数性假设。