Evaluation of clinical prediction models (part 2): how to undertake an external validation study.
Riley RD., Archer L., Snell KIE., Ensor J., Dhiman P., Martin GP., Bonnett LJ., Collins GS.
External validation studies are an important but often neglected part of prediction model research. In this article, the second in a series on model evaluation, Riley and colleagues explain what an external validation study entails and describe the key steps involved, from establishing a high quality dataset to evaluating a model’s predictive performance and clinical usefulness.