Patrick Royston

What do we mean by validating a prognostic model?

Prognostic models are used in medicine for investigating patient outcome in relation to patient and disease characteristics. Such models do not always work well in practice, so ...

Multiple imputation using chained equations: Issues and guidance for practice

Abstract Multiple imputation by chained equations is a flexible and practical approach to handling missing data. We describe the principles of the method and show how to impute ...

Multiple Imputation of Missing Values

Following the seminal publications of Rubin about thirty years ago, statisticians have become increasingly aware of the inadequacy of “complete-case” analysis of datasets with m...

Multiple Imputation of Missing Values: Update of Ice

Royston (2004) introduced mvis, an implementation for Stata of MICE, a method of multiple multivariate imputation of missing values under missing-at-random (MAR) assumptions. In...

Imputing missing covariate values for the Cox model

Abstract Multiple imputation is commonly used to impute missing data, and is typically more efficient than complete cases analysis in regression analysis when covariates have mi...

Multiple Imputation of Missing Values: Update

This article describes a substantial update to mvis, which brings it more closely in line with the feature set of S. van Buuren and C. G. M. Oudshoorn's implementation of the MI...

Multivariable Model‐Building

Multiple Imputation of Missing Values: Further Update of Ice, with an Emphasis on Categorical Variables

Multiple imputation of missing data continues to be a topic of considerable interest and importance to applied researchers. In this article, the ice package for multiple imputat...

A New Framework for Managing and Analyzing Multiply Imputed Data in Stata

A new set of tools is described for performing analyses of an ensemble of datasets that includes multiple copies of the original data with imputations of missing values, as requ...

Multiple Imputation of Missing Values: Further Update of Ice, with an Emphasis on Interval Censoring