Meta-analyses involving cross-over trials: methodological issues.

BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials. METHODS: The char...

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Главные авторы: Elbourne, DR, Altman, D, Higgins, J, Curtin, F, Worthington, H, Vail, A
Формат: Journal article
Язык:English
Опубликовано: 2002
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author Elbourne, DR
Altman, D
Higgins, J
Curtin, F
Worthington, H
Vail, A
author_facet Elbourne, DR
Altman, D
Higgins, J
Curtin, F
Worthington, H
Vail, A
author_sort Elbourne, DR
collection OXFORD
description BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials. METHODS: The characteristics of these trials are outlined, with detailed examples of methods for analysis for both continuous and binary data. These case studies are then extended into the context of a meta-analysis. The Cochrane Library was surveyed to assess current practice for synthesis. RESULTS: Methods are described for continuous and binary data for use both when the necessary paired data are given and also when they need to be calculated or imputed, and some suggestions are provided to help people wishing to synthesize data from cross-over trials into meta-analyses. The survey suggested that about 8% of the trials in the Cochrane library were cross-over trials and 18% of the reviews referred to such trials, although there was no consistent approach to their inclusion into the reviews. CONCLUSIONS: Methods do exist for including valuable information from two-period, two-treatment cross-over trials into quantitative reviews. However, poor reporting of cross-over trials will often impede attempts to perform a meta-analysis using the available methods.
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spelling oxford-uuid:a6afa929-eeea-42d4-a1de-f45296d52c032022-03-27T02:48:59ZMeta-analyses involving cross-over trials: methodological issues.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a6afa929-eeea-42d4-a1de-f45296d52c03EnglishSymplectic Elements at Oxford2002Elbourne, DRAltman, DHiggins, JCurtin, FWorthington, HVail, A BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials. METHODS: The characteristics of these trials are outlined, with detailed examples of methods for analysis for both continuous and binary data. These case studies are then extended into the context of a meta-analysis. The Cochrane Library was surveyed to assess current practice for synthesis. RESULTS: Methods are described for continuous and binary data for use both when the necessary paired data are given and also when they need to be calculated or imputed, and some suggestions are provided to help people wishing to synthesize data from cross-over trials into meta-analyses. The survey suggested that about 8% of the trials in the Cochrane library were cross-over trials and 18% of the reviews referred to such trials, although there was no consistent approach to their inclusion into the reviews. CONCLUSIONS: Methods do exist for including valuable information from two-period, two-treatment cross-over trials into quantitative reviews. However, poor reporting of cross-over trials will often impede attempts to perform a meta-analysis using the available methods.
spellingShingle Elbourne, DR
Altman, D
Higgins, J
Curtin, F
Worthington, H
Vail, A
Meta-analyses involving cross-over trials: methodological issues.
title Meta-analyses involving cross-over trials: methodological issues.
title_full Meta-analyses involving cross-over trials: methodological issues.
title_fullStr Meta-analyses involving cross-over trials: methodological issues.
title_full_unstemmed Meta-analyses involving cross-over trials: methodological issues.
title_short Meta-analyses involving cross-over trials: methodological issues.
title_sort meta analyses involving cross over trials methodological issues
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AT curtinf metaanalysesinvolvingcrossovertrialsmethodologicalissues
AT worthingtonh metaanalysesinvolvingcrossovertrialsmethodologicalissues
AT vaila metaanalysesinvolvingcrossovertrialsmethodologicalissues