IMPORTANCE Although brief intervention is effective for reducing problem alcohol use, few data exist on its effectiveness for reducing problem drug use, a common issue in disadvantaged populations seeking care in safety-net medical settings (hospitals and community health clinics serving low-income patients with limited or no insurance). OBJECTIVE To determine whether brief intervention improves drug use outcomes compared with enhanced care as usual. DESIGN, SETTING, AND PARTICIPANTS A randomized clinical trial with blinded assessments at baseline and at 3, 6, 9, and 12 months conducted in 7 safety-net primary care clinics in Washington State. Of 1621 eligible patients reporting any problem drug use in the past 90 days, 868 consented and were randomized between April 2009 and September 2012. Follow-up participation was more than 87% at all points. INTERVENTIONS Participants received a single brief intervention using motivational interviewing, a handout and list of substance abuse resources, and an attempted 10-minute telephone booster within 2 weeks (n = 435) or enhanced care as usual, which included a handout and list of substance abuse resources (n = 433). MAIN OUTCOMES AND MEASURES The primary outcomes were self-reported days of problem drug use in the past 30 days and Addiction Severity Index–Lite (ASI) Drug Use composite score. Secondary outcomes were admission to substance abuse treatment; ASI composite scores for medical, psychiatric, social, and legal domains; emergency department and inpatient hospital admissions, arrests, mortality, and human immunodeficiency virus risk behavior. RESULTS Mean days used of the most common problem drug at baseline were 14.40 (SD, 11.29) (brief intervention) and 13.25 (SD, 10.69) (enhanced care as usual); at 3 months postintervention, means were 11.87 (SD, 12.13) (brief intervention) and 9.84 (SD, 10.64) (enhanced care as usual) and not significantly different (difference in differences, β = 0.89 [95% CI, –0.49 to 2.26]). Mean ASI Drug Use composite score at baseline was 0.11 (SD, 0.10) (brief intervention) and 0.11 (SD, 0.10) (enhanced care as usual) and at 3 months was 0.10 (SD, 0.09) (brief intervention) and 0.09 (SD, 0.09) (enhanced care as usual) and not significantly different (difference in differences, β = 0.008 [95% CI, –0.006 to 0.021]). During the 12 months following intervention, no significant treatment differences were found for either variable. No significant differences were found for secondary outcomes. CONCLUSIONS AND RELEVANCE A one-time brief intervention with attempted telephone booster had no effect on drug use in patients seen in safety-net primary care settings. This finding suggests a need for caution in promoting widespread adoption of this intervention for drug use in primary care.

Objectives To determine if urine drug tests (UDTs) can detect underreporting of drug use (i.e., negative self-report, but positive UDT) and identify patient characteristics associated with underreporting when treating substance use disorders in primary care. Methods Self-reported use (last 30 days) and UDTs were gathered at baseline, 3, 6, 9, and 12 months from 829 primary care patients participating in a drug use intervention study. Rates of underreporting were calculated for all drugs, cannabis, stimulants, opioids, and sedatives. Logistic regressions were used to identify characteristics associated with underreporting. Results 40% (n=331) of participants denied drug use in the prior 30 days despite a corresponding positive UDT during at least one assessment. Levels of underreporting during one or more assessments were 3% (n=22) for cannabis, 20% (n=167) for stimulants, 27% (n=226) opioids, and 13% (n=106) for sedatives. Older (OR=1.04), female (OR=1.66), or disabled (OR=1.42) individuals were more likely to underreport any drug use. Underreporting of stimulant use was also more likely in individuals with lower levels of educational attainment, previous arrests, and family and social problems. Underreporting of opioid use was more likely in those with other drug problems, but less likely in those with better physical health, more severe alcohol and psychiatric comorbidities, and African-Americans. Conclusions With the exception of cannabis, UDTs are important assessment tools when treating drug use disorders in primary care. UDTs might be particularly helpful when treating patients who are older, female, disabled, have legal and social problems, and have more severe drug problems.