Cited by 92Statistical Methods in EpidemiologySepsis Diagnosis and TreatmentMachine Learning in Healthcare

External validation of prognostic models for critically ill patients required substantial sample sizes

Peek, N., Arts, D.G.T., Bosman, R.J., van der Voort, P.H.J., de Keizer, N.F.·2007·Journal of Clinical Epidemiology

Abstract

Objective To investigate the behavior of predictive performance measures that are commonly used in external validation of prognostic models for outcome at intensive care units (ICUs).Study design and setting Four prognostic models (Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation II, and the Mortality Probability Models II) were evaluated in the Dutch National Intensive Care Evaluation registry database. For each model discrimination (AUC), accuracy (Brier score), and two calibration measures were assessed on data from 41,239 ICU admissions. This validation procedure was repeated with smaller subsamples randomly drawn from the database, and the results were compared with those obtained on the entire data set.Results Differences in performance between the models were small. The AUC and Brier score showed large variation with small samples. Standard errors of AUC values were accurate but the power to detect differences in performance was low. Calibration tests were extremely sensitive to sample size. Direct comparison of performance, without statistical analysis, was unreliable with either measure.Conclusion Substantial sample sizes are required for performance assessment and model comparison in external validation. Calibration statistics and significance tests should not be used in these settings. Instead, a simple customization method to repair lack-of-fit problems is recommended.

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Crossref · 10.1016/j.jclinepi.2006.08.011

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Authors
Peek, N., Arts, D. G. T., Bosman, R. J., van der Voort, P. H. J., & de Keizer, N. F.
Affiliations
  • Amsterdam UMC Location University of Amsterdam (NL)
  • OLVG (NL)
Corresponding author
Peek, N.
Venue
Journal of Clinical Epidemiology
Publisher
Elsevier BV
Published
2007-05
Volume
60
Issue
5
Pages
491.e1-491.e13
ISSN
0895-4356 (ISSN-L)
OpenAlex
W1997812541
Cited by
92
References
35
Citations by year
2026: 1 · 2025: 5 · 2024: 4 · 2023: 5 · 2022: 6 · 2021: 2 · 2020: 4 · 2019: 4 · 2018: 3 · 2017: 5 · 2016: 5 · 2015: 8 · 2014: 10 · 2013: 3 · 2012: 4
FWCI
6.63
Type
journal article
Language
en
Open access
closed
Locations
  • Journal of Clinical Epidemiology (publishedVersion)
  • PubMed (publishedVersion)
  • Pure Amsterdam UMC (publishedVersion)
  • Data Archiving and Networked Services (DANS) (submittedVersion)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
  • Health Sciences › Medicine › Epidemiology › Sepsis Diagnosis and Treatment
  • Physical Sciences › Computer Science › Artificial Intelligence › Machine Learning in Healthcare
Keywords
external validation, prognostic model, intensive care unit, sample size, model discrimination, calibration, AUC, Brier score, APACHE II score, SAPS II, ICU mortality prediction, lack of fit, model comparison
MeSH terms
Aged, Calibration, Epidemiologic Methods, Female, Humans, Intensive Care Units, Male, Middle Aged, Netherlands, Prognosis, Critical Illness, Outcome Assessment, Health Care

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