Trends in the use of cannabis products in Canada and the USA, 2018 - 2020: Findings from the International Cannabis Policy Study

BACKGROUND AND AIMS: There is little information on consumption patterns across the diverse range of cannabis product types. This paper examines trends in consumption patterns in Canada and the United States (US) between 2018-2020. DESIGN: Repeat cross-sectional surveys were conducted as part of the International Cannabis Policy Study online survey in 2018 (n=27,024), 2019 (n=45,426), and 2020 (n=45,180). SETTING: Respondents were recruited from commercial panels in Canada and US states that had and had not legalized non-medical cannabis (US 'legal' and 'illegal' states, respectively). PARTICIPANTS: Respondents were male and female participants aged 16-65 years. MEASUREMENTS: Data on frequency and consumption amounts were collected for nine types of cannabis products, including dried flower and processed products (e.g., oils and concentrates). Consumers were also asked about mixing cannabis with tobacco. Socio-demographic information was collected. FINDINGS: Dried flower was the most commonly used product, although use in the past 12 months declined between 2018 and 2020 in Canada (81% to 73%), US legal (78% to 72%) and illegal states (81% to 76%; p<0.05 for all). Prevalence of past 12-month use increased for virtually all other product forms, although prevalence of daily use remained stable across years. In 2020, edibles and vape oils were the most commonly used products after flower. Use of non-flower products was highest in US legal states, although similar trends were observed in all jurisdictions. Males were more likely to report using processed products, and vape oils were the most commonly processed product among 16-20-year-olds. Daily use of cannabis flower increased in US legal and illegal states, and average joint size increased across all jurisdictions over time. CONCLUSIONS: Dried flower remains the dominant product in Canada and the US; however, use of processed cannabis products has increased, with the largest increases observed in legal cannabis markets.