The application of meta-analysis within a matched-pair randomized control trial: an illustration testing the effects...

Use of meta-analytic strategies to test intervention effects is an important complement to traditional design-based analyses of intervention effects in randomized control trials. In the present paper, we suggest that meta-analyses within the context of matched-pair designs can provide useful insight into intervention effects. We illustrate the advantages to this analytic strategy by examining the effectiveness of the Communities That Care (CTC) prevention system on 8th-grade delinquent behavior in a randomized matched-pair trial. We estimate the intervention effect within each of the matched-pair communities, aggregate the effect sizes across matched pairs to derive an overall intervention effect, and test for heterogeneity in the effect of CTC on delinquency across matched pairs of communities. The meta-analysis finds that CTC reduces delinquent behavior and that the effect of CTC on delinquent behavior varies significantly across communities. The use of meta-analysis in randomized matched-pair studies can provide a useful accompaniment to other analytic approaches because it opens the possibility of identifying factors associated with differential effects across units or matched pairs in the context of a randomized control trial.