Cannabis use, comorbidities, and prescription medication use among older adults in a large healthcare system in Los Angeles, CA 2019-2020.

OBJECTIVE

To describe the reported prevalence of cannabis use and co-use with prescription medications among older adult patients attending primary care (PC) clinics in Los Angeles, CA.

METHODS

We used electronic health record (EHR) data from sixty PC clinics part of a university-based, urban healthcare system. Patients' ≥50 years of age with an annual physical examination between July 2019 and May 2020 were eligible for inclusion (n = 42,555). Cannabis use was assessed by clinic staff at the time of the visit and recorded in the EHR. We also used EHR data on clinical characteristics including current prescriptions and comorbidities.

RESULTS

The median age was 63 years (range: 50-101) and 56% were female. Recent cannabis use was reported by 7.6%, which was higher than tobacco use (4.0%; p < 0.01). Prevalence of cannabis use was higher among patients prescribed psychotropic medications. For instance, 10.9% of patients prescribed benzodiazepines reported cannabis use as compared with 7.3% among patients without a prescription for benzodiazepines (p < 0.01). Patients with neurologic/musculoskeletal medications such as antiepileptics also had a higher prevalence of cannabis use when compared with those without these prescriptions (13.6% vs. 7.6% respectively; p < 0.01) as did those who were prescribed muscle relaxants (10.3% vs. 7.5% respectively; p < 0.01). After adjusting for age, sex, race/ethnicity, and comorbidities those prescribed medications for psychiatric (adjusted OR = 1.5; 95% CI 1.4-1.7), respiratory (adjusted OR = 1.2; 95% CI 1.1-1.3), or neurologic conditions (adjusted OR = 1.4; 95% CI 1.2-1.5) had increased odds of cannabis use compared with those not prescribed these medications.

DISCUSSION: The prevalence of cannabis use among older adults attending PC clinics in a university-based healthcare system was higher among those prescribed medications, which may interact with cannabis. These findings suggest that key groups of older patients who may benefit from routine PC screening for cannabis use and brief advice.