title: Validation of a heteroscedastic hazards regression model.
abstract: A Cox-type regression model accommodating heteroscedasticity, with a power factor of the baseline cumulative hazard, is investigated for analyzing data with crossing hazards behavior. Since the approach of partial likelihood cannot eliminate the baseline hazard, an overidentified estimating equation (OEE) approach is introduced in the estimation procedure. It by-product, a model checking statistic, is presented to test for the overall adequacy of the heteroscedastic model. Further, under the heteroscedastic model setting, we propose two statistics to test the proportional hazards assumption. Implementation of this model is illustrated in a data analysis of a cancer clinical trial.
authors.affiliation: School of Public Health, China Medical College, 91 Hsueh-Shih Rd., Taichung 40443, Taiwan. honda@mail.cmc.edu.tw
authors.forename: Hong-Dar Isaac
authors.initials: HD
authors.lastname: Wu
authors.forename: Fushing
authors.initials: F
authors.lastname: Hsieh
authors.forename: Chen-Hsin
authors.initials: CH
authors.lastname: Chen
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D015233:Models, Statistical; D009369:Neoplasms / Q000401:mortality / Q000628:therapy; D016016:Proportional Hazards Models; D020379:Risk Adjustment; D016019:Survival Analysis; D013997:Time Factors