Meta-analysis combining parallel and cross-over clinical trials. II: Binary outcomes.

Journal article

We examine different methods to pool binary outcomes used both in parallel and cross-over trials. Odds ratio (OR) estimators obtained from joint conditional probabilities in cross-over trials, such as the Mantel-Haenszel and Peto methods, are compared to an OR estimator using marginal results of cross-over trials. When there is correlation between the outcomes in the two cross-over periods, joint conditional ORs differ from marginal ORs and cannot be combined with OR estimates from parallel trials. The marginal OR estimate is independent of the between-period correlation and it includes a correction for cross-over correlation in the variance estimate. As its computation is similar in cross-over and parallel trials, it is the method of choice to pool results from parallel and cross-over trials in a combined design meta-analysis.

Authors: Curtin, F; Elbourne, D; Altman, D

• Publication status: Published
• Journal: Stat Med
• Volume: 21
• Issue: 15
• Pages: 2145-2159
• Publication date: 2002-08-15
• DOI: 10.1002/sim.1206
• ISSN: 0277-6715
• Language: English
• Keywords: Glomerular Filtration Rate; Statistics as Topic; Humans; Diabetic Nephropathies; Light Coagulation; Albuminuria; Clinical Trials as Topic; Diet, Protein-Restricted; Meta-Analysis as Topic; Cross-Over Studies; Diabetic Retinopathy; Odds Ratio