Single-item Screening Tool for Cannabis Use Disorder Opens Opportunities in Primary Care

Medical and nonmedical cannabis use—and cannabis use disorders (CUD)—have been increasing in the US, especially in states that have legalized its use. A brief, valid cannabis screen in primary care could facilitate the identification and treatment of unhealthy cannabis use. Two studies evaluated the real-world screening performance of a single-item cannabis screen* and characterized patterns of medical and nonmedical cannabis use and CUD in a single health system in a US state with legalized nonmedical cannabis use. To assess CUD and describe patterns of use among the 108,950 adults who completed routine cannabis screening in primary care, 5000 patients were randomly sampled and 1688 (34 percent) completed a detailed survey.

• In this sample (mean age 51 years, 56 percent women, 74 percent White, 65 percent commercially insured, 48 percent with ≥4 years of college), 93 percent had no CUD, 5 percent had mild CUD, and 2 percent had moderate-to-severe CUD.
• Performance of the single-item screening response of monthly or more cannabis use was excellent, with sensitivity of 71 percent and specificity of 92 percent for any CUD, and sensitivity of 96 percent and specificity of 89 percent for moderate-to-severe CUD.
• Among respondents with any cannabis use…
  • the prevalence of CUD was 21 percent and moderate-to-severe CUD was 7 percent.
  • 42 percent reported medical cannabis use only, 25 percent reported nonmedical use only, and 33 percent reported both reasons for use.
• While the prevalence of any CUD did not differ depending on reasons for use, the prevalence of moderate-to-severe CUD was higher among people with nonmedical use (7 percent) or among those with both reasons for use (8 percent), compared with those with medical use only (1 percent).

* The single-item screen, embedded in a routine annual 7-item behavioral health questionnaire, asked: “How often in the past year have you used marijuana?” The response options were: “never,” “less than monthly,” “monthly,” “weekly,” or “daily or almost daily.”

Comments: In this relatively high-resource population in a state that legalized nonmedical cannabis use, a single-item cannabis screen embedded in usual care showed excellent screening performance, providing an opportunity to identify CUD in primary care. Assessing reasons for cannabis use may be helpful in identifying people with nonmedical use who are more likely to have moderate-to-severe CUD, and those with medical cannabis use who may benefit from a discussion of the risks and limited medical benefits of cannabis, as well as safer alternatives. While prior studies have not shown brief interventions based on screening for non-prescribed substance use in primary care to be effective, this targeted cannabis screening opens new opportunities.

Joseph Merrill, MD, MPH

References: Matson TE, Lapham GT, Bobb JF, et al. Validity of the Single-Item Screen-Cannabis (SIS-C) for cannabis use disorder screening in routine care. JAMA Netw Open. 2022;5(11):e2239772.

Lapham GT, Matson TE, Bobb JF, et al. Prevalence of cannabis use disorder and reasons for use among adults in a US state where recreational cannabis use is legal. JAMA Netw Open. 2023;6(8):e2328934.