title: The utility of collateral informant assessment in college alcohol research: results from a longitudinal prevention trial.
abstract: OBJECTIVE
  Collateral informants have been used to assess independently the validity of college student self-report data. However, it is unclear under what conditions collateral reports might be valid and useful in college research. We present two studies that examine aspects of these issues using data from 1,264 college student participants in a brief intervention prevention trial conducted at a public university.
  
  
  METHODS
  The first study describes the characteristics and predictors of agreement on reports of alcohol use and problems from 219 student-collateral informant pairs. The second study investigates potential "pipeline effects"; that is, whether collateral verification resulted in changes in student self-reports on two subsequent survey assessments over 1 year using longitudinal data from 1,264 students.
  
  
  RESULTS
  Little support was found for the assumption that nondependent college drinkers underreport drinking behaviors and consequences. Collaterals who reported more occasions of drinking together, higher confidence in the report and a close relationship with the participant provided reports that were more consistent with participant drinking reports. No evidence was found that pipeline effects of collateral verification improve the accuracy of college student self-reports at future assessments.
  
  
  CONCLUSIONS
  The results from this study are consistent with much of the published literature showing that using collateral reports to verify the self-reports of college students (and adults) may result in increased, not decreased, misclassification error. These findings suggest that the time and expense required to collect collateral data in the college setting has limited utility and may be better spent on establishing the proper assessment conditions that will foster accurate and honest self-reporting.
authors.affiliation: Department of Psychology, CPRC Building, Room 48W, University of Rhode Island, 2 Chafee Road, Kingston, Rhode Island 02881, USA. rlaforge@uri.edu
authors.forename: Robert G
authors.initials: RG
authors.lastname: Laforge
authors.forename: Brian
authors.initials: B
authors.lastname: Borsari
authors.forename: John S
authors.initials: JS
authors.lastname: Baer
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000517:prevention & control*; D019973:Alcohol-Related Disorders / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D040261:Harm Reduction; D006801:Humans; D007398:Interpersonal Relations; D007406:Interview, Psychological; D008297:Male; D010379:Peer Group; D010507:Periodicity; D013334:Students / Q000706:statistics & numerical data*; D014342:Truth Disclosure; D014495:Universities