Cnaan A, Ryan L
Department of Biostatistics, Harvard School of Public Health, Boston, MA.
Stat Med. 1989 Oct;8(10):1255-68. doi: 10.1002/sim.4780081009.
Clinicians often wish to use data from clinical trials or hospital databases to study disease natural history. Of particular interest are estimated survival and prognostic factors. In this context, it may be appropriate to measure survival from diagnosis or some other time origin, possibly prior to study entry. We describe the application of methods for truncated survival data, and compare these with the standard product limit estimator and proportional hazards models in the measurement of survival from entry. Theoretical considerations suggest that analysis of survival from entry may under- or overestimate the survival distribution of interest, depending on the shape of the true underlying hazard. Analogous results hold for the coefficients from a proportional hazards model. We illustrate our findings with data from a multicenter clinical trial and a hospital database.
临床医生常常希望利用临床试验或医院数据库的数据来研究疾病的自然史。特别令人感兴趣的是估计生存率和预后因素。在这种情况下，从诊断或其他某个时间点（可能在研究入组之前）来衡量生存率可能是合适的。我们描述了截断生存数据方法的应用，并将其与标准乘积限估计器和比例风险模型在衡量从入组开始的生存率方面进行比较。理论上的考虑表明，根据真实潜在风险的形状，对从入组开始的生存情况进行分析可能会低估或高估感兴趣的生存分布。比例风险模型的系数也有类似结果。我们用来自一项多中心临床试验和一个医院数据库的数据来说明我们的发现。
