BACKGROUND: Substance use screening is widely encouraged in healthcare settings, but the lack of a screening approach that fits easily into clinical workflows has restricted its broad implementation. The Substance Use Brief Screen (SUBS) was developed as a brief, self-administered instrument to identify unhealthy use of tobacco, alcohol, illicit drugs, and prescription drugs. We evaluated the validity and test-retest reliability of the SUBS in adult primary care patients.
METHODS: Adults age 18-65 were enrolled from urban safety net primary care clinics to self-administer the SUBS using touch-screen tablet computers for a test-retest reliability study (n=54) and a two-site validation study (n=586). In the test-retest reliability study, the SUBS was administered twice within a 2-week period. In the validation study, the SUBS was compared to reference standard measures, including self-reported measures and saliva drug tests. We measured test-retest reliability and diagnostic accuracy of the SUBS for detection of unhealthy use and substance use disorder for tobacco, alcohol, and drugs (illicit and prescription drug misuse).
RESULTS: Test-retest reliability was good or excellent for each substance class. For detection of unhealthy use, the SUBS had sensitivity and specificity of 97.8% (95% CI 93.7 to 99.5) and 95.7% (95% CI 92.4 to 97.8), respectively, for tobacco; and 85.2% (95% CI 79.3 to 89.9) and 77.0% (95% CI 72.6 to 81.1) for alcohol. For unhealthy use of illicit or prescription drugs, sensitivity was 82.5% (95% CI 75.7 to 88.0) and specificity 91.1% (95% CI 87.9 to 93.6). With respect to identifying a substance use disorder, the SUBS had sensitivity and specificity of 100.0% (95% CI 92.7 to 100.0) and 72.1% (95% CI 67.1 to 76.8) for tobacco; 93.5% (95% CI 85.5 to 97.9) and 64.6% (95% CI 60.2 to 68.7) for alcohol; and 85.7% (95% CI 77.2 to 92.0) and 82.0% (95% CI 78.2 to 85.3) for drugs. Analyses of area under the receiver operating curve (AUC) indicated good discrimination (AUC 0.74-0.97) for all substance classes. Assistance in completing the SUBS was requested by 11% of participants.
CONCLUSIONS: The SUBS was feasible for self-administration and generated valid results in a diverse primary care patient population. The 4-item SUBS can be recommended for primary care settings that are seeking to implement substance use screening.
A brief patient self-administered substance use screening tool for primary care: Two-site validation study of the Substance Use Brief Screen (SUBS)
American Journal of Medicine, 128 (7), 784.e9-784.e19. doi: 10.1016/j.amjmed.2015.02.007. PMCID: PMC4475501.