Time-Dependent Hazard Ratio: Modeling and Hypothesis Testing With Application in Lupus Nephritis
研究了狼疮性肾炎患者未治疗病程与生存的关联，用回归样条将风险比建模为时间的灵活函数，并提出了比例风险和无关联的假设检验方法。
Abstract We investigate the association between duration of untreated disease and survival in lupus nephritis, a rare rheumatologic disease. In this case, as in many other studies of survival, a priori considerations suggest that the effect of the predictor on hazard may change with increasing follow-up time. To accommodate such situations, we use regression splines to model the hazard ratio as a flexible function of time. We propose model-based tests of the hypotheses of hazards proportionality and of no association. We evaluate the accuracy of estimation and inference in simulations and also present analysis of a larger medical data set.