Talk is cheap: measuring drinking outcomes in clinical trials.

OBJECTIVE To evaluate the correspondence among measures of self-reported drinking, standard biological indicators and the reports of collateral informants, and to identify patient characteristics associated with observed discrepancies among these three sources of research data. METHOD Using data collected from a large-scale clinical trial of treatment matching with alcoholics (N = 1,726), these three alternative outcome measures were compared at the time of admission to treatment and at 12 months after the end of treatment. RESULTS Patient self-reports and collateral reports agreed most (97.1%) at treatment admission when heavy drinking was unlikely to be denied. In contrast, liver function tests were relatively insensitive, with positive serum gamma-glutamyl transpeptidase (GGTP) values obtained from only 39.7% of those who admitted to heavy drinking. At 15-month follow-up the correspondence between client self-report and collateral report decreased to 84.7%, but agreement with blood chemistry values increased to 51.6%. When discrepancies occurred, they still indicated that the client' s self-report is more sensitive to the amount of drinking than the biochemical measures. Patients who presented discrepant results tended to have more severe drinking problems, more previous treatments, higher levels of pretreatment drinking and significantly greater levels of cognitive impairment, all of which could potentially interfere with accurate recall. CONCLUSIONS In clinical trials using self-selected research volunteers, biochemical tests and collateral informant reports do not add sufficiently to self-report measurement accuracy to warrant their routine use. Resources devoted to collecting these alternative sources of outcome data might be better invested in interview procedures designed to increase the validity of self-report information.

[1]  A. Haines,et al.  Randomised controlled trial of general practitioner intervention in patients with excessive alcohol consumption. , 1988, BMJ.

[2]  M. Irwin,et al.  Use of laboratory tests to monitor heavy drinking by alcoholic men discharged from a treatment program. , 1988, The American journal of psychiatry.

[3]  Linda C. Sobell,et al.  Timeline Follow-Back A Technique for Assessing Self-Reported Alcohol Consumption , 1992 .

[4]  S. Borg,et al.  Detection of relapses in alcohol-dependent patients using carbohydrate-deficient transferrin: improvement with individualized reference levels during long-term monitoring. , 1995, Alcoholism, clinical and experimental research.

[5]  L. Sobell,et al.  Validity of alcoholic's self-reports: duration data. , 1981, The International journal of the addictions.

[6]  F. D. Del Boca,et al.  Estimating measurement error in alcohol dependence symptomatology: findings from a multisite study. , 1997, Drug and alcohol dependence.

[7]  F. D. Del Boca,et al.  Measurement of drinking behavior using the Form 90 family of instruments. , 1994, Journal of studies on alcohol. Supplement.

[8]  O. Nilssen The Tromsø Study: identification of and a controlled intervention on a population of early-stage risk drinkers. , 1991, Preventive medicine.

[9]  G. Edwards A later follow-up of a classic case series: D. L. Davies's 1962 report and its significance for the present. , 1985, Journal of studies on alcohol.

[10]  J Chick,et al.  Counselling problem drinkers in medical wards: a controlled study. , 1985, British medical journal.

[11]  R. Anton,et al.  Carbohydrate-deficient transferrin and gamma-glutamyltransferase as markers of heavy alcohol consumption: gender differences. , 1994, Alcoholism, clinical and experimental research.

[12]  C. Diclemente,et al.  Project MATCH: Rationale and methods for a multisite clinical trial matching patients to alcoholism treatment , 1993 .

[13]  R. Anton,et al.  Carbohydrate-deficient transferrin as a measure of immoderate drinking: remaining issues. , 1994, Alcoholism, clinical and experimental research.

[14]  F. Iber,et al.  Liver toxicity encountered in the Veterans Administration trial of disulfiram in alcoholics. , 1987, Alcoholism, clinical and experimental research.

[15]  L. Sobell,et al.  Effects of three interview factors on the validity of alcohol abusers' self-reports. , 1981, The American journal of drug and alcohol abuse.

[16]  G A Marlatt,et al.  Verbal report methods in clinical research on alcoholism: response bias and its minimization. , 1987, Journal of studies on alcohol.

[17]  R. Anton,et al.  Multisite clinical trials in alcoholism treatment research: organizational, methodological and management issues. , 1994, Journal of studies on alcohol. Supplement.