A Cross-Sectional and Prospective Comparison of Medicinal Cannabis Users and Controls on Self-Reported Health

Introduction: Despite widespread legalization, the impact of medicinal cannabis use on patient-level health and quality of life (QOL) has not been carefully evaluated. The objective of this study was to characterize self-reported demographics, health characteristics, QOL, and health care utilization of Cannabis Users compared with Controls. Methods: A longitudinal, cross-sectional web-based survey study was completed between April 2016 and February 2018. Study participants (n=1276) were a convenience sample of either patients with a diagnosed health condition or caregivers of a patient with a diagnosed health condition registered with the Realm of Caring Foundation (a nonprofit organization dedicated to therapeutic cannabis research and education). Participants were invited through e-mail to complete follow-up assessments every 3 months with 33% of participants completing one or more prospective follow-ups. Assessments included self-reported demographics, health care utilization, medication use, pain, anxiety, depression, sleep, and QOL. Cannabis Users (n=808) were compared with Controls (n=468) using negative binomial regression and linear mixed effects models testing the effect of initiation, cessation, and maintenance of medicinal cannabis use. Results: Cannabis Users self-reported significantly better QOL [t(1054)=-4.19, p<0.001], greater health satisfaction [t(1045)=-4.14, p<0.001], improved sleep [children: t(224)=2.90, p<0.01; adults: [t(758)=3.03, p<0.01], lower average pain severity [t(1150)=2.34, p<0.05], lower anxiety [t(1151)=4.38, p<0.001], and lower depression [t(1210)=5.77, p<0.001] compared with Controls. Cannabis Users reported using fewer prescription medications (rate ratio [RR]=0.86; 95% confidence interval [CI]: 0.77-0.96) and were less likely to have a past-month emergency department visit (RR=0.61; 95% CI: 0.44-0.84) or hospital admission (RR=0.54; 95% CI: 0.34-0.87). Controls who initiated cannabis use after baseline showed significant health improvements at follow-up, and the magnitude of improvement mirrored the between-group differences observed at baseline. Conclusions: Cannabis use was associated with improved health and QOL. Longitudinal testing suggests that group differences may be due to the medicinal use of cannabis. Although bias related to preexisting beliefs regarding the health benefits of cannabis in this sample should be considered, these findings indicate that clinical trials evaluating the efficacy of defined cannabinoid products for specific health conditions are warranted.