Background: The majority of research examining college drinking utilizes self-report data, and collateral reports have been used to verify participants’ self-reported alcohol use.
Methods: This meta-analytic integration examined the correspondence of over 970 collateral and participant dyads in the college setting.
Results and Conclusions: Results indicated that there is little bias (mean difference) between collateral estimates of participant drinking and participant’s self-report. A cumulative meta-analysis revealed that this (null) effect was stable and unlikely to be altered by subsequent research or the existence of unpublished studies. Analysis of the agreement between collaterals and participant estimates (measured by intraclass correlation coefficients; ICCs) revealed moderate levels of agreement (mean ICC = 0.501). Examination of predictors of both bias and agreement in collateral and participant reports indicates a possible intentional and protective underreporting on the part of the collaterals. Ways to reduce this bias are discussed along with the value of using collaterals to verify participant self-report in the college setting.