Welcome to Missing Data Solutions

October 5, 2025

Most examples and solutions will be concentrated on Missing Data topics. Posts may also concern Regression modeling, Clinical Prediction models and Spline regression modeling. Most examples originate from FAQs asked during statistical consultations or during courses. Examples are provided for applied researchers and frequenly in RStudio. RStudio is an open source free package with a lot of possibilities, making it easy to share code so that you can use the code example and adjust it to your own needs.

Recalibration of the Cox model Baseline Hazard Function after Shrinkage

October 1, 2025

This post is about the offset procedure of the Cox model after shrinkage of the coefficients, followed by recalibration of the baseline hazard function. This seems straightforward to apply like with the logistic regression model but some caveats remain. These will be unraveled here.

Prediction Modeling with the Cox model - all about the baseline hazard

September 9, 2025

This post is about the internal and external validation of Cox regression models and how to adjust the baseline hazard function.

External validation of a Cox prognostic model

February 4, 2021

This blog shows how to externally validate a Cox regression prognostic model according to all steps in the paper of Royston & Altman. R code available.

Multiple Imputation and Cross-validation

February 4, 2021

With the function psfmi_perform of the psfmi package it is possible to combine Cross-validation with Multiple Imputation for internal validation.

Steps to externally validate a prediction model

January 1, 2021

External validation means that the performance of a prediction model is studied in a new (external) patient dataset that is not used to develop the model. It is important to use the correct predicted probabilities to evaluate if the external validation of the model is successful!

Model Stability analysis after Multiple Imputation

January 11, 2020 in Model Stability, Bootstrapping, BIF

With the psfmi_stab function of the psfmi package it is possible to do important stability analyses of the models and predictors selected during backward selection after multiple imputation.

Welcome to Missing Data Solutions

Recalibration of the Cox model Baseline Hazard Function after Shrinkage

Prediction Modeling with the Cox model - all about the baseline hazard

External validation of a Cox prognostic model

Multiple Imputation and Cross-validation

Steps to externally validate a prediction model

Model Stability analysis after Multiple Imputation

Martijn W Heymans