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A parametric dynamic survival model applied to breast cancer survival times
Author(s) -
Hemming K.,
Shaw J. E. H.
Publication year - 2002
Publication title -
journal of the royal statistical society: series c (applied statistics)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.205
H-Index - 72
eISSN - 1467-9876
pISSN - 0035-9254
DOI - 10.1111/1467-9876.00278
Subject(s) - covariate , parametric statistics , gibbs sampling , proportional hazards model , statistics , breast cancer , markov chain monte carlo , survival analysis , mathematics , econometrics , bayesian probability , parametric model , cancer , medicine
Summary. Much current analysis of cancer registry data uses the semiparametric proportional hazards Cox model. In this paper, the time‐dependent effect of various prognostic indicators on breast cancer survival times from the West Midlands Cancer Intelligence Unit are investigated. Using Bayesian methodology and Markov chain Monte Carlo estimation methods, we develop a parametric dynamic survival model which avoids the proportional hazards assumption. The model has close links to that developed by both Gamerman and Sinha and co‐workers: the log‐base‐line hazard and covariate effects are piecewise constant functions, related between intervals by a simple stochastic evolution process. Here this evolution is assigned a parametric distribution, with a variance that is further included as a hyperparameter. To avoid problems of convergence within the Gibbs sampler, we consider using a reparameterization. It is found that, for some of the prognostic indicators considered, the estimated effects change with increasing follow‐up time. In general those prognostic indicators which are thought to be representative of the most hazardous groups (late‐staged tumour and oldest age group) have a declining effect.