This article presents a random effects model that uses effect sizes (ES) and quality scores to integrate results from investigations.
An empirical example is given with data obtained from a meta-analysis on the effectiveness of physical activity in the prevention of bone loss in healthy postmenopausal women.
A Medline search was performed to locate relevant studies published in French or English between January 1966 and May 1996.
Three independent reviewers extracted data from studies.
Effect sizes were calculated according to the method of Hedges and Olkin.
A modified version of Chalmers'scale was utilized to calculate quality scores.
DerSimonian and Laird's method with incorporation of the quality scores was used to estimate the overall effect size.
Quality scores and the inverse of the variances were included as weights when combining studies.
The overall estimate and standard error (SE) of the effect of physical activity on spinal hone mineral density loss in healthy postmenopausal women was ESoverall=0.4263 (1.1361).
When compared to other meta-analysis methods such as the fixed effects model and the model of DerSimonian and Laird without the quality score (DL), the new model generated comparable estimators (fixed effects model's ESoverall (SE)=1.2724 (0.0139), DLs ESoverall (SE)=0.3958 (1.2370)). Due to the heterogeneity that existed between studies, a random effects model was more appropriate then a fixed effects model. (...)
Mots-clés Pascal : Ostéoporose, Perte, Masse osseuse, Postménopause, Echelle évaluation, Qualité, Taille échantillon, Analyse statistique, Epidémiologie, Méthodologie, Modèle mathématique, Métaanalyse, Homme, Femelle, Système ostéoarticulaire pathologie, Ostéopathie
Mots-clés Pascal anglais : Osteoporosis, Loss, Bone mass, Postmenopause, Evaluation scale, Quality, Sample size, Statistical analysis, Epidemiology, Methodology, Mathematical model, Metaanalysis, Human, Female, Diseases of the osteoarticular system, Bone disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0511384
Code Inist : 002B30A01A1. Création : 23/03/1999.