Medical Cannabis Use Among Older Adults in Canada: Self-Reported Data on Types and Amount Used, and Perceived Effects

Abstract

Background: Medical cannabis use is growing among older adults. In this retrospective study, we aimed to assess the characteristics of older medical cannabis users including the indications, type and amount of cannabis used, perceived changes in symptoms after cannabis use, change in dose of concurrent medications, and adverse effects. Methods: Data were collected between October 2014 and October 2020 from patients who were consulting the Canada-wide network of clinics of a medical cannabis provider and who were willing to answer questionnaires based on their medical status. The current study included older adults (≥ 65 years) who completed questionnaires at intake and first follow-up visits. Data were summarized with descriptive statistics, which were compared between men and women with t tests or chi-squared tests. Tests of proportions assessed categorical responses for perceived effects after cannabis use. Logistic regression was used to assess trends in cannabis usage. Results: Data included that from 9766 older adult users at intake (mean ± SD age = 73.2 ± 6.8 years, females = 60.0%), among whom 4673 (females = 61.4%) returned for follow-up after 90.6 ± 58 days. The most common primary indication for which medical cannabis was sought was pain (67.7%), which was more common in women, whereas oncological and neurological conditions were more common in men. At follow-up, cannabis oil was used by 81.0% of older adults, among whom compositions containing only or mostly cannabidiol (CBD) had been used by 83.6%. Adverse effects reported by older adults at the follow-up visit included dry mouth (12.8%), drowsiness (8.6%), and dizziness (4.0%). The majority of older adults reported improvements in pain (72.7%, z = 1482.6, p < 0.0001, compared to worsening or no change), sleep (64.5%, z = 549.4, p < 0.0001), and mood (52.8%, z = 16.4, p < 0.0001), with 35.6% reporting use of a reduced dose of opioids and 19.9% a reduced dose of benzodiazepines. Interpretation: Among older adults, medical cannabis is used more often by women, with CBD-containing cannabis oils being the most commonly used. Users reported improved pain, sleep, and mood symptoms at follow-up after cannabis use. This study describes the patterns of use of medical cannabis by older adults and highlights the need for research to determine appropriate indications, precise doses of active ingredients, and short- and long-term outcomes among older adults.