Davidov O, Zelen M
Biostatistics Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Lifetime Data Anal. 1998;4(4):309-27. doi: 10.1023/a:1009626002246.
This paper investigates the urn sampling analogue for the score statistic relating survival to covariates assuming a proportional hazard model. The exact permutation distribution can be calculated as well as the exact low order moments for arbitrary censoring patterns. The asymptotic distribution of the score statistic is an easy consequence. The method is naturally extended to deal with the multivariate case, time varying covariates and interval censoring. Finally the relationship between the censoring process, the survival times and covariates are studied considering different reference sets for the distribution of the score statistic. Some assumptions about the censoring process are investigated and as a consequence the effect of censoring is clarified.
本文研究了在假定比例风险模型的情况下，与生存和协变量相关的得分统计量的瓮抽样类似物。可以计算精确的排列分布以及任意删失模式下的精确低阶矩。得分统计量的渐近分布是一个容易得出的结果。该方法自然地扩展到处理多变量情况、时变协变量和区间删失。最后，考虑得分统计量分布的不同参考集，研究了删失过程、生存时间和协变量之间的关系。研究了关于删失过程的一些假设，从而阐明了删失的影响。
