Study Questions Methods Used in Drug-Use Polls
WASHINGTON--The General Accounting Office has challenged the accuracy of the three leading surveys of adolescent and adult drug use.
The G.A.O. reported last month that the surveys' methodologies were "questionable'' and often led to underestimates about the prevalence of drug use.
The annual studies, which cost the federal government a total of $16.5 million in 1991, are: the High School Senior Survey, the National Household Survey on Drug Abuse, and the Drug Use Forecasting Survey.
While the G.A.O. calls the surveys "highly developed'' in their design, it faults them for relying too much on self-reporting techniques. That method has proved unreliable, the agency contends.
The report also claims the surveys routinely exclude groups perceived as having serious drug problems.
The H.S.S.S., which has tracked drug use among high school seniors since 1975 and is widely viewed as a barometer for drug use among young people, may not be a very comprehensive measurement, the report says.
In the study, a group of University of Michigan researchers surveys 15,000 to 19,000 public and private high school students every year.
The G.A.O. report notes that truants, absentees, and dropouts--who represent more than one-fifth of the student population--are not included in the study. As dropouts are thought to have higher rates of drug use than children who stay in school, the H.S.S.S. estimates of adolescent drug use may be artificially low.
The H.S.S.S. survey, which has reported gradual declines in drug use among young people for the past decade, also does a poor job of surveying minority populations, the G.A.O. report alleges.
The report also found big flaws in the other studies. In 1991, for example, the N.H.S.D.A., which surveys adolescent and adult drug use, overestimated the number of frequent cocaine users by 230,000, the report claims.
Single copies of the report, "Drug Use Measurement: Strengths, Limitations, and Recommendations for Improvement,'' GAO/PEMD-93-18, are available for free from the U.S. General Accounting Office, P.O. Box 6015, Gaithersburg, Md. 20884-6015. Additional copies cost $2 each.--J.P.