As cannabis use grows, primary care needs to integrate screening for patients

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As more states allow use of cannabis for medical or recreational use, primary care physicians need to integrate routine cannabis screenings, according to a new study.

Researchers found one in six patients in primary care reported using the drug, and 34.7% of those patients using at levels that indicate moderate to high risk of cannabis use disorder. The authors said few health care systems offer cannabis screenings in primary care, but that needs to change.

“Patients may not tell their primary care providers about their cannabis use, and their doctors may not ask about it,” lead author Lillian Gelberg, MD, said in an accompanying news release. Gelberg is professor of family medicine at the David Geffen School of Medicine at UCLA and of health policy and management at the UCLA Fielding School of Public Health.

“Not asking patients about their cannabis use results in a missed opportunity for opening up doctor-patient communication regarding use of cannabis generally and for management of their symptoms,” she said.

Context around the country

Primary care physicians are more likely to encounter patients who use cannabis. As of March, 38 states, with three territories and Washington, D.C., allow medical cannabis use, and 24 of those states allow recreational use. Meanwhile, product potency is growing with higher levels of THC, the study said.

“The changing legal landscape has likely played a substantial role in shaping public perception, leading to a decrease in stigma and an increase in the perception that cannabis use involves no risk,” the study said.

As of 2020, the U.S. Preventive Services Task Force recommends primary care physicians and other clinicians screen adults for substance use, including cannabis, and valid, patient-reported assessment are available. But “routine screening in primary care remains limited,” the researchers said.

Study results

The study involved 175,734 adult patients who had annual wellness visits from January 2021 to May 2023 in a primary care clinic of the University of California – Los Angeles Health system. The researchers asked patients to voluntarily complete cannabis use surveys during pre-appointment check-ins via the Epic patient portal.

Among them:

• 29,898, or 17%, reported cannabis use in the past three months. There were 14,939 men users and 14,916 women users.
• Patients aged 18 to 29 years had the greatest prevalence of use, at 7,592 patients.
• Patients aged 60 years and older had just 8.5% use, at 4,200 patients.
• 11,989 patients, or 40.1%, reported using only once or twice in the past three months.
• 7,325 patients, or 24.5%, reported using weekly.
• 5,621 patients, or 18.8%, reported using daily or almost daily.

Reasons for use

Reasons for using the drug varied. Among the patients, 4,375, or 15.6%, reported using cannabis for strictly medical reasons. Medical and nonmedical reasons applied to 8,734 patients, or 31.1%, and 14,944 patients, or 53.3%, reported only nonmedical use, according to the study. Even so, 21,986 patients, ore 75.7%, said they used the drug to manage symptoms including sleep (56%), stress (50.2%), worry or anxiety (36.3%), and nonspecific pain (31.7%).

The results aligned with another study that found that type of cannabis use is “clinically under-recognized.” Without specific screening, physicians and other clinicians may not ask about, and patients may not disclose marijuana use, the study said.

Male patients and younger adults were at greatest risk of disordered use, and those groups could benefit from a primary care clinician-based intervention, the study said.

Prevalence of cannabis use was lowest among patients living in disadvantaged neighborhoods, but they had higher risk of cannabis use disorder, the study said. But that group of patients was underrepresented in the study, and influence of neighborhood on substance use is limited or conflicting, so the researchers said they could not draw strong conclusions about specific links to risk of cannabis use disorder.

Limitations

The researchers noted the findings were based on patient reporting. While California has legalized cannabis, some patients may remain reluctant to reveal cannabis use to their physicians, the study said. The patient-reported symptoms were not validated against diagnose conditions in patient electronic health records. The data were collected during restrictive phases of the COVID-19 pandemic, which may have resulted in more cannabis use, according to the study. The results may not apply to health systems in states where adult cannabis use remains illegal.

“Cannabis Use Reported by Patients Receiving Primary Care in a Large Health System” was published June 5 in JAMA Network Open.