title: Regression splines for threshold selection in survival data analysis.
abstract: The Cox proportional hazards model restricts the hazard ratio to be linear in the covariates. A survival model based on data from a clinical trial is developed using spline functions with variable knots to estimate the log hazard function. Moreover, the main point of the method is that a knot, seen as free parameters for a piecewise linear spline, represents a break point in the log hazard function which may be interpreted as a threshold value. The likelihood ratio test is used to select the final model and to determine the threshold number for a covariate. Confidence intervals for these threshold values are computed by bootstrapping the data. Two examples illustrate the method.
authors.affiliation: Laboratoire de Biostatistique, Institut Universitaire de Recherche Clinique, 641, avenue Gaston Giraud, 34093 Montpellier, France.
authors.forename: N
authors.initials: N
authors.lastname: Molinari
authors.forename: J P
authors.initials: JP
authors.lastname: Daurès
authors.forename: J F
authors.initials: JF
authors.lastname: Durand
mesh_terms: D018288:Carcinoma, Small Cell / Q000188:drug therapy; D002986:Clinical Trials as Topic / Q000379:methods*; D016001:Confidence Intervals; D003627:Data Interpretation, Statistical; D005260:Female; D016027:Heart Transplantation / Q000401:mortality; D006801:Humans; D016013:Likelihood Functions; D008175:Lung Neoplasms / Q000188:drug therapy; D008297:Male; D009716:Numerical Analysis, Computer-Assisted; D010751:Phosphopyruvate Hydratase / Q000097:blood; D011379:Prognosis; D016016:Proportional Hazards Models; D012044:Regression Analysis; D016019:Survival Analysis
chemical_list: D010751:Phosphopyruvate Hydratase