Reliability of self-reports of low ethanol consumption by problem drinkers over 18 months of follow-up.

Forty-eight male problem drinkers participating in an 18-month prospective evaluation of an outpatient alcohol treatment program were interviewed monthly about their drinking and related behaviors; their collateral informants were interviewed every two months during this same period to corroborate the subjects' self-reports. A high degree of consistency was found between subjects' and collaterals' reports of the subjects' drinking behavior, including days of low ethanol consumption. These results indicate that subjects' drinking behavior can be precisely and reliably assessed over a long interval. The finding that reliable self-reports of low ethanol consumption can be obtained from problem drinkers participating in an outcome evaluation study is important, since nonproblem drinking is gaining acceptance as an achievable treatment goal for some alcohol abusers.