SPSURV: Stata module to fit split population survival ('cure') model

spsurv estimates what economists refer to as split population survival models (Schmidt and Witte, 1989) and biostatisticians refer to as cure models, for the case where survival times are intrinsically discrete or are recorded in grouped form, e.g. in months. (Cf. the continuous time lognormal cure model lncure.) Standard survival models assume that the prob(eventual failure) > 0 for all individuals. By contrast split population models suppose that a proportion never fail. spsurv estimates by ML this proportion together with the parameters characterising the hazard rate for the remainder of the population. For the latter, spsurv estimates a discrete-time proportional hazard (cloglog) model. It is a form of 'mover-stayer' model.