Non-PH parametric survival modelling

Non-PH parametric survival modelling is developed within the frame- work of the multiple logistic function. The family considered comprises three basic models: (a) a PH model, (b) an accelerated life model and (c) a model which is non-proportional hazards and non-accelerated life. The family is generalised by means of a Gamma frailty extension which is shown to accommodate crossing haz- ards data. These extensions lead naturally to the concept of a Multi-Parameter Regression model described by Burke and MacKenzie (2016). The new models are used to analyse two sets of survival data and the advantages of the methods are discussed.