Renato Valladares Panaro

arXiv2026

Using the spsurv R package for semi-parametric time-to-event analysis

We present spsurv, an R package for semi-parametric time-to-event regression based on Bernstein-polynomial estimation of unknown baseline functions. The package provides a unified modelling interface for proportional hazards (PH), proportional odds (PO), and accelerated failure time (AFT) models for right-censored data, with either maximum likelihood or Bayesian estimation via Stan. Smooth baseline hazard, odds-function, or log-time structures are estimated without assuming a parametric baseline family, while retaining familiar hazard-ratio, odds-ratio, and time-ratio interpretations. We describe methodology, implementation, and syntax; evaluate finite-sample behaviour in a Monte Carlo study; and illustrate usage with oncology trials.

stat.ME↗

arXiv2020

spsurv: An R package for semi-parametric survival analysis

Software development innovations and advances in computing have enabled more complex and less costly computations in medical research (survival analysis), engineering studies (reliability analysis), and social sciences event analysis (historical analysis). As a result, many semi-parametric modeling efforts emerged when it comes to time-to-event data analysis. In this context, this work presents a flexible Bernstein polynomial (BP) based framework for survival data modeling. This innovative approach is applied to existing families of models such as proportional hazards (PH), proportional odds (PO), and accelerated failure time (AFT) models to estimate unknown baseline functions. Along with this contribution, this work also presents new automated routines in R, taking advantage of algorithms available in Stan. The proposed computation routines are tested and explored through simulation studies based on artificial datasets. The tools implemented to fit the proposed statistical models are combined and organized in an R package. Also, the BP based proportional hazards (BPPH), proportional odds (BPPO), and accelerated failure time (BPAFT) models are illustrated in real applications related to cancer trial data using maximum likelihood (ML) estimation and Markov chain Monte Carlo (MCMC) methods.

stat.AP↗