Abstract
Validation of prediction models is highly recommended and increasingly common in the literature. A
systematic review of validation studies is therefore helpful, with meta-analysis needed to summarise the
predictive performance of the model being validated across different settings and populations. The aims
of this article are (1) to provide guidance for systematically reviewing and meta-analysing the existing
evidence on a specific prediction model, (2) to discuss ‘good practice’ when quantitatively summarizing the
predictive performance of the model across studies and (3) to provide recommendations for interpreting
meta-analysis estimates of model performance. We present key steps of the meta-analysis and illustrate
each step in an exemplar review where we summarize the discrimination and calibration performance of
the EuroSCORE for predicting operative mortality in patients undergoing coronary artery bypass grafting.