Peter C. Austin

Variable Selection for the Propensity Score Model: Beyond Main Effects and Linear Relations

ABSTRACT Propensity score methods are frequently used to estimate treatment effects in observational studies. The propensity score is usually estimated using a logistic regression model with additive and linear effects. The limited literature on variable selection for the propens...

The Impact of the Number and the Size of Clusters on Prediction Performance of the Stratified and the Conditional Shared Gamma Frailty Cox Proportional Hazards Models

ABSTRACT Researchers in biomedical research often analyze data that are subject to clustering. Development and validation of risk prediction models generally assumes independence of observations. For survival outcomes, the Cox proportional hazards (PH) regression model is commonl...