Confidence intervals for the first crossing point of two hazard functions
- 126 Downloads
The phenomenon of crossing hazard rates is common in clinical trials with time to event endpoints. Many methods have been proposed for testing equality of hazard functions against a crossing hazards alternative. However, there has been relatively few approaches available in the literature for point or interval estimation of the crossing time point. The problem of constructing confidence intervals for the first crossing time point of two hazard functions is considered in this paper. After reviewing a recent procedure based on Cox proportional hazard modeling with Box-Cox transformation of the time to event, a nonparametric procedure using the kernel smoothing estimate of the hazard ratio is proposed. The proposed procedure and the one based on Cox proportional hazard modeling with Box-Cox transformation of the time to event are both evaluated by Monte–Carlo simulations and applied to two clinical trial datasets.
KeywordsClinical trials Crossing point Hazard functions Kernel estimates Undersmoothing bandwidth
- Cote R, Battista RN, Abrahamowicz M, Langlois Y, Bourque F, Mackey A (1995) Lack of effect of Aspirin in asymptomatic patients with Carotid Bruits and substantial Carotid Narrowing. Ann Intern Med 123(9): 649–655Google Scholar
- Remontet L, Bossard N, Belot A, Esteve J, The French network of cancer registries FRANCIM (2007) An overall strategy based on regression models to estimate relative survival and model the effects of prognostic factors in cancer survival studies. Stat Med 26(10):2214–2228Google Scholar