A single question helps identify patients at higher risk of cannabis use disorder

One in five people who use cannabis daily at risk for moderate to severe use disorder

A new Kaiser Permanente study finds that the prevalence and severity of cannabis use disorder (CUD) increases with more frequent use, with 20% of people reporting daily cannabis use at risk for moderate to severe CUD.

The study evaluated use of a screening tool in primary care settings that asks patients one question — how often they used cannabis in the last year. As daily marijuana use outpaces daily alcohol consumption, the researchers emphasized that it is important for health care providers to discuss cannabis consumption with patients and help them understand the potential risks.

The study, published by Journal of General Internal Medicine, included more than 1,500 Kaiser Permanente Washington members who self-reported cannabis use in the clinical setting and responded to a confidential cannabis survey. Patients who reported daily cannabis use had 44.6% prevalence of any CUD and a 20.3% prevalence of moderate-severe CUD. They were also more likely to report inhalation of cannabis products as the primary mode of consumption.

“In order for clinicians to follow up with patients who might benefit from additional support, we need to better understand what the possible risks are and who is at risk for negative impacts,” said Gwen Lapham, PhD, MPH, MSW, lead author of the study and an assistant investigator at Kaiser Permanente Washington Health Research Institute (KPWHRI). “But previously there wasn’t data on the difference in risk for a patient who uses cannabis once a week, for example, versus someone who is using it once a month or less frequently.”

Cannabis use disorder is defined by 11 possible symptoms, which include trying and failing to quit using cannabis, experiencing cravings, continuing use even though it causes problems, and needing more cannabis to feel the same effects. A mild case involves 2 or 3 symptoms, while a moderate or severe case involves more than 4 or 5.

The researchers looked at data from 1,589 patients in primary care clinics at Kaiser Permanente Washington who self-reported their cannabis use in the past year on a routine screening questionnaire. The screening tool has been in regular use in primary care at Kaiser Permanente Washington since 2015.

Patients completed a confidential survey that included a diagnostic tool for CUD. The findings showed that prevalence of any CUD (mild, moderate, or severe) and prevalence of moderate to severe CUD increased with more frequent cannabis use. Among patients who used cannabis weekly, 11% reported 4 or more symptoms of CUD, and 33% reported 2 or more. For those who used cannabis less than monthly, the prevalence dropped to 0.9% and 13% for moderate-severe and any CUD, respectively.

The researchers wrote that the study findings provide further support for use of the single-question screening. The responses can be used by clinical teams to help patients understand their risk of CUD and to determine which patients might benefit from further screening.

The study also found that most patients, including more than 85% of patients who use daily, reported that the primary way they used cannabis was through inhalation (smoking, vaping, or dabbing), which is associated with greater risk of negative health outcomes than other methods. 

“There’s a lot we still don’t know about the effects of cannabis, especially very high-potency products that are becoming more widely available,” Lapham said. “Understanding the experiences people are having and the difference in risk is important so we can be sure that care teams have the information they need to advise patients and start a conversation about possible health effects for patients with higher-risk cannabis use.”

This study was funded by the National Institute on Drug Abuse Clinical Trials Network.

KPWHRI coauthors are Jennifer Bobb, PhD; Casey Luce, MSPH; Malia Oliver, BA; Leah Hamilton, PhD; Noorie Hyun, PhD; and Theresa Matson, PhD, MPH.

​​​​​By Amelia Apfel