Internal-external cross-validation helped to evaluate the generalizability of prediction models in large clustered datasets

J Clin Epidemiol. 2021 Sep:137:83-91. doi: 10.1016/j.jclinepi.2021.03.025. Epub 2021 Apr 6.

Abstract

Objective: To illustrate how to evaluate the need of complex strategies for developing generalizable prediction models in large clustered datasets.

Study design and setting: We developed eight Cox regression models to estimate the risk of heart failure using a large population-level dataset. These models differed in the number of predictors, the functional form of the predictor effects (non-linear effects and interaction) and the estimation method (maximum likelihood and penalization). Internal-external cross-validation was used to evaluate the models' generalizability across the included general practices.

Results: Among 871,687 individuals from 225 general practices, 43,987 (5.5%) developed heart failure during a median follow-up time of 5.8 years. For discrimination, the simplest prediction model yielded a good concordance statistic, which was not much improved by adopting complex strategies. Between-practice heterogeneity in discrimination was similar in all models. For calibration, the simplest model performed satisfactorily. Although accounting for non-linear effects and interaction slightly improved the calibration slope, it also led to more heterogeneity in the observed/expected ratio. Similar results were found in a second case study involving patients with stroke.

Conclusion: In large clustered datasets, prediction model studies may adopt internal-external cross-validation to evaluate the generalizability of competing models, and to identify promising modelling strategies.

Keywords: Calibration; Discrimination; Heterogeneity; Model comparison; Prediction model; Validation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Cluster Analysis*
  • Datasets as Topic / statistics & numerical data*
  • Forecasting*
  • Humans
  • Models, Statistical*