Can a Single-Question Alcohol Screen Also Detect Drug Use?

Recent studies have validated a single-question screen* to detect unhealthy alcohol use. Researchers examined 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions data (N=43,093 adults) to determine whether this question could also identify individuals with drug use and drug use disorders (DUDs) in the following categories: any illicit drugs, marijuana, cocaine, and/or illicit prescription drugs. The criterion standard was a structured diagnostic interview delivered by a trained interviewer.

• The prevalence of past-year drug use was as follows: any past-year use, 6.2%; past-year DUD, 2.0%; past year drug dependence, 0.6%.

• For any drug use, DUD, or dependence, sensitivity ranged from 63–72% and specificity ranged from 77–79% using the best cutoff of drinking 5+/4+ drinks on 1 or more occasions per year.

• For any marijuana use, sensitivity ranged from 72–78%, and specificity ranged from 77–78%.

• For cocaine use, sensitivity was 77.6% and specificity was 84.5% using the best cutoff of drinking 5+/4+ drinks on 7 or more occasions per year.

• The single-question screen did not achieve >60% sensitivity for illicit prescription drug use.

• Across drug use categories, the proportion of people with positive screens who in fact had the condition (positive predictive values) ranged from 1.9–23.4% for any use, 0.9–9.6% for DUD, and 0.5–1.9% for dependence. The lowest values were for cocaine, followed by illicit prescription drugs, then marijuana, then any drug.

Comments:

Detection of drug use may be seen as added value to screening for unhealthy alcohol use, a practice recommended by the US Preventive Services Task Force. It’s important to note, however, that the single-question screen was conducted by trained staff during a research interview and not a clinical setting, after several other questions about alcohol and drug use had been asked. Thus, the results require validation in real-world clinical settings. Furthermore, this method had relatively low sensitivity for identifying illicit prescription drug use, an increasingly important issue in primary-care settings.

Alexander Y. Walley, MD, MSc

Reference:

Dawson DA, Compton WM, Grant BF. Frequency of 5+/4+ drinks as a screener for drug use and drug-use disorders. J Stud Alcohol Drugs. 2010;71 (5):751–760.