parametric proportional hazard regression
On Fri, 7 Jul 2006, Valentin Dimitrov wrote:
I am trying to find a suitable R-function for parametric proportional hazard regressions. The package survival contains the coxph() function which performs a Cox regression which leaves the base hazard unspecified, i.e. it is a semi-parametric method. The package Design contains the function pphsm() which is good for parametric proportional hazard regressions when the underlying base distribution is "weibull" or "exponential". But what if I need a parametric proportional hazard model with the other "usual" distributions like '"gaussian"', '"logistic"', '"lognormal"'and '"loglogistic"?
Those are not proportional hazards families of distributions. That is, if the distribution is gaussian for one value of the hazard ratio parameters it will not be gaussian for any other value. You can get accelerated failure models with these distributions using survreg() in the survival package. -thomas Thomas Lumley Assoc. Professor, Biostatistics tlumley at u.washington.edu University of Washington, Seattle