Evaluating the Utility of Collateral Informants in College Drinking Studies

• Activity Number: 492
• Type: Topic Contributed
• Date/Time: Wednesday, August 1, 2012 : 10:30 AM to 12:20 PM
• Sponsor: Social Statistics Section
• Author(s): Michael Fendrich*+ and Daniel Fuhrmann and Lisa Berger and Charles Plate and Joseph Jones
• Companies: University of Wisconsin-Milwaukee and University of Wisconsin-Milwaukee and University of Wisconsin-Milwaukee and U.S. Drug Testing Laboratories and U.S. Drug Testing Laboratories

Abstract

It has been common practice in studies of college drinking behavior to employ collateral informants to verify self-reports of drinking. Despite this practice, we are aware of no studies that have evaluated the utility of these collateral reports. Here we report on a study that ascertained student drinking behavior via biomarkers (ethyglucoronide in hair and fingernails) and self-report in over 600 randomly selected students. For a subset of respondents we also collected collateral informant report. The results suggested that collaterals and study subjects were consistent with each other with respect to their reports of heavy drinking (phi =.52; X2 = 21.92). Inspection of kappa coefficients suggested that the correspondence between collateral informants and drug test results paralleled the correspondence between original informants and these same results. Twelve of 16 informants who underreported their heavy drinking according to hair tests were not identified as heavy drinkers by collaterals. Seven of 9 informants who underreported their drinking according to fingernail tests were not identified as heavy drinkers by collaterals. Collateral informants provide a useful source of