External validation of clinical prediction models: simulation-based sample size calculations were more reliable than rules-of-thumb.

ABSTRACT:

Introduction

Sample size "rules-of-thumb" for external validation of clinical prediction models suggest at least 100 events and 100 non-events. Such blanket guidance is imprecise, and not specific to the model or validation setting. We investigate factors affecting precision of model performance estimates upon external validation, and propose a more tailored sample size approach.

Methods

Simulation of logistic regression prediction models to investigate factors associated with precision of performance estimates. Then, explanation and illustration of a simulation-based approach to calculate the minimum sample size required to precisely estimate a model's calibration, discrimination and clinical utility.

Results

Precision is affected by the model's linear predictor (LP)

SUBMITTER: Snell KIE 

PROVIDER: S-EPMC8352630 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature