Increasing Use of Cannabis for Medical Purposes Among U.S. Residents, 2013–2020

Abstract

Cannabis use for medical purposes is legalized across 39 states and the District of Columbia in the U.S. The objective of this study was to evaluate temporal trends and correlates of cannabis use for medical purposes in the U.S. Data from the 2013-2020 National Survey on Drug Use and Health were used. Since 2013, medical cannabis use has been assessed using a dichotomous question asking whether any medical cannabis use was recommended by a doctor among those who used cannabis in the past 12 months. A modified Poisson model was used to estimate the average annual percentage change in medical cannabis use from 2013 to 2020. The analyses were repeated for key sociodemographic and clinical subgroups. Data were analyzed from September to November 2022. The prevalence of U.S. residents using cannabis for medical purposes increased significantly from 1.2% in 2013-2014 to 2.5% in 2019-2020, with an average annual percentage change of 12.9% (95% CI=10.4, 15.5), and many of sociodemographic and clinical subgroups showed similar significant increases in cannabis use for medical purposes. In the multivariable-adjusted model, living in a state that legalized medical cannabis remained significantly associated with medical cannabis use (AOR=4.10; 95% CI=3.68, 4.56). The study documents a continued nationwide increase in the use of cannabis for diverse medical purposes between 2013 and 2020, two decades after the first state passed legalizing legislation.