The utility of collateral informants in substance use research involving college students

Collateral informants have been routinely included in substance abuse treatment research to corroborate subject self-reported alcohol and other drug use. However, only a few studies to date have examined subject–collateral correspondence with respect to non-clinical populations (e.g., college students). The purpose of the present study was to examine the associations between college students self-reported substance use and corresponding collateral (i.e., friends') reports. A total of 100 subject–collateral pairs were recruited from psychology courses at a large public university located in the Southeastern, United States. Subjects and collaterals provided information specific to their own, as well as their friend's, recent (i.e., last 90-days) substance use. Study data yielded moderate to good, statistically significant, correlations between subject–friend pairs for each type of substance use. Discrepancy analyses revealed that the majority of subjects reported greater substance use relative to their collateral reports. This pattern of response (i.e., subject reporting greater use) is consistent with the extant literature. In addition, the friend's personal substance use appeared to influence his/her report of the subject's alcohol and other drug use. It appears that college student self-reports regarding alcohol and other drug use are reasonably accurate.