Wang M C, Brookmeyer R, Jewell N P
Department of Biostatistics, Johns Hopkins University, Baltimore, Maryland 21205.
Biometrics. 1993 Mar;49(1):1-11.
In prospective cohort studies individuals are sometimes recruited according to a certain cross-sectional sampling criterion. A prevalent cohort is defined as a group of individuals who have a certain disease at enrollment into the study. Statistical models for the analysis of prevalent cohort data are considered when the onset or diagnosis time of the disease is known. The incident proportional hazards model, where the time scale is duration with disease, is compared to the prevalent proportional hazards model, where the fundamental time scale is follow-up time. In certain cases the time of enrollment may coincide with another event (such as the initiation of treatment). This situation is also considered and its limitations highlighted. To illustrate the methodological ideas discussed in the paper, the analysis of data from an observational study of zidovudine (ZVD) in patients with the acquired immunodeficiency syndrome (AIDS) is presented.
在前瞻性队列研究中，个体有时是根据特定的横断面抽样标准招募的。现患队列被定义为在研究入组时患有某种疾病的一组个体。当疾病的发病或诊断时间已知时，会考虑用于分析现患队列数据的统计模型。将时间尺度为患病持续时间的发病比例风险模型与基本时间尺度为随访时间的现患比例风险模型进行比较。在某些情况下，入组时间可能与另一个事件（如开始治疗）重合。本文也考虑了这种情况并强调了其局限性。为了说明本文讨论的方法学思想，展示了对艾滋病患者齐多夫定（ZVD）观察性研究数据的分析。
