title: Using collaterals to validate self-reports of problem drinkers: any impact on client attrition and quantity of drinking reported?
abstract: OBJECTIVE
  To explore the impact of asking for a collateral on respondent attrition and the impact of providing versus not providing a collateral on self-reported drinking.
  
  
  METHODS
  As part of a larger trial assessing the efficacy of self-help materials for problem drinkers, respondents were randomly assigned to be asked or not asked to provide a collateral at the time of their 6-month follow-up.
  
  
  RESULTS
  While there was no significant impact of client attrition, respondents who were asked for a collateral and provided one reported higher levels of alcohol consumption at the 6-month follow-up as compared to those who were asked for a collateral but did not provide one.
  
  
  CONCLUSIONS
  Providing a collateral may have an impact on respondent's self-reported drinking. Alternate explanations for this finding are discussed.
authors.affiliation: Centre for Addiction and Mental Health, Toronto, Ontario, Canada. John_Cunningham@camh.net
authors.forename: John A
authors.initials: JA
authors.lastname: Cunningham
authors.forename: T Cameron
authors.initials: TC
authors.lastname: Wild
authors.forename: Joanne
authors.initials: J
authors.lastname: Cordingley
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000523:psychology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010352:Patient Dropouts / Q000523:psychology*; D015203:Reproducibility of Results; D012648:Self Care; D012650:Self Disclosure; D016896:Treatment Outcome