Snell, KI and Ensor, J and Debray, TP and Moons, KG and Riley, RD (2017) Meta-analysis of prediction model performance across multiple studies: Which scale helps ensure between-study normality for the C-statistic and calibration measures? Stat Methods Med Res. 962280217705678 - ?. ISSN 1477-0334

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Abstract

If individual participant data are available from multiple studies or clusters, then a prediction model can be externally validated multiple times. This allows the model's discrimination and calibration performance to be examined across different settings. Random-effects meta-analysis can then be used to quantify overall (average) performance and heterogeneity in performance. This typically assumes a normal distribution of 'true' performance across studies. We conducted a simulation study to examine this normality assumption for various performance measures relating to a logistic regression prediction model. We simulated data across multiple studies with varying degrees of variability in baseline risk or predictor effects and then evaluated the shape of the between-study distribution in the C-statistic, calibration slope, calibration-in-the-large, and E/O statistic, and possible transformations thereof. We found that a normal between-study distribution was usually reasonable for the calibration slope and calibration-in-the-large; however, the distributions of the C-statistic and E/O were often skewed across studies, particularly in settings with large variability in the predictor effects. Normality was vastly improved when using the logit transformation for the C-statistic and the log transformation for E/O, and therefore we recommend these scales to be used for meta-analysis. An illustrated example is given using a random-effects meta-analysis of the performance of QRISK2 across 25 general practices.

Item Type: Article
Uncontrolled Keywords: validation; performance statistics; C-statistic; discrimination; calibration; meta-analysis; between-study distribution; heterogeneity; simulation
Subjects: ?? C-statistic ??
R Medicine > RA Public aspects of medicine
?? Validation ??
?? between-study distribution ??
?? calibration ??
?? discrimination ??
?? heterogeneity ??
?? meta-analysis ??
?? performance statistics ??
?? simulation ??
Divisions: Faculty of Medicine and Health Sciences > Primary Care Health Sciences
Related URLs:
Depositing User: Symplectic
Date Deposited: 01 Jun 2017 09:10
Last Modified: 01 Jun 2017 09:10
URI: http://eprints.keele.ac.uk/id/eprint/3520

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