The effect of recreational cannabis legalization on rates of traffic injury in Canada.

AIMS: To measure the impact of Canada's recreational cannabis legalization (RCL) in October 2018 and the subsequent impact of the coronavirus disease 2019 (COVID-19) lockdowns from March 2020 on rates of emergency department (ED) visits and hospitalizations for traffic injury. DESIGN: An interrupted time series analysis of rates of ED visits and hospitalizations in Canada recorded in population-based databases from January/April 2010 to March 2021. SETTING: ED visits in Ontario and Alberta and hospitalizations in Ontario, Alberta, British Columbia, the Prairies (Manitoba and Saskatchewan) and the Maritimes (Nova Scotia, New Brunswick, Newfoundland and Prince Edward Island). PARTICIPANTS: Monthly counts of presentations to the ED or hospital for motor vehicle injury or pedestrian/cyclist injury, used to calculate monthly rates per 100 000 population. MEASUREMENTS: An occurrence of one or more International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada (ICD-10-CA) code for motor vehicle injury (V20-V29, V40-V79, V30-V39 and V86) and pedestrian/cyclist injury (V01-V09 and V10-V19) within the National Ambulatory Care Reporting System and Discharge Abstract Database. FINDINGS: There were no statistically significant changes in rates of ED visits and hospitalizations for motor vehicle or pedestrian/cyclist injury after RCL after accounting for multiple testing. After COVID-19, there was an immediate decrease in the rate of ED visits for motor vehicle injury that was statistically significant only in Ontario (level change ß = -16.07 in Ontario, 95% CI = -20.55 to -11.60, P = 0.000; ß = -10.34 in Alberta, 95% CI = -17.80 to -2.89, P = 0.008; α of 0.004) and no changes in rates of hospitalizations. CONCLUSIONS: Canada's recreational cannabis legalization did not notably impact motor vehicle and pedestrian/cyclist injury. The rate of emergency department visits for motor vehicle injury decreased immediately after COVID-19 lockdowns, resulting in rates below post-recreational cannabis legalization levels in the year after COVID-19.

The association between recreational cannabis legalization, commercialization and cannabis-attributable emergency department visits in Ontario, Canada: an interrupted time-series analysis.

BACKGROUND AND AIMS: Recreational cannabis was legalized in Canada in October 2018. Initially, the Government of Ontario (Canada's largest province) placed strict limits on the number of cannabis retail stores before later removing these limits. This study measured changes in cannabis-attributable emergency department (ED) visits over time, corresponding to different regulatory periods. DESIGN: Interrupted time-series design using population-level data. Two policy periods were considered; recreational cannabis legalization with strict store restrictions (RCL, 17 months) and legalization with no store restrictions [recreational cannabis commercialization (RCC), 15 months] which coincided with the COVID-19 pandemic. Segmented Poisson regression models were used to examine immediate and gradual effects in each policy period. SETTING: Ontario, Canada. PARTICIPANTS: All individuals aged 15-105 years (n = 13.8 million) between January 2016 and May 2021. MEASUREMENTS: Monthly counts of cannabis-attributable ED visits per capita and per all-cause ED visits in individuals aged 15+ (adults) and 15-24 (young adults) years. FINDINGS: We observed a significant trend of increasing cannabis-attributable ED visits pre-legalization. RCL was associated with a significant immediate increase of 12% [incident rate ratio (IRR) = 1.12, 95% confidence interval (CI) = 1.02-1.23] in rates of cannabis-attributable ED visits followed by significant attenuation of the pre-legalization slope (monthly slope change IRR = 0.98, 95% CI = 0.97-0.99). RCC and COVID-19 were associated with immediate significant increases of 22% (IRR = 1.22, 95% CI = 1.09-1.37) and 17% (IRR = 1.17, 95% CI = 1.00-1.37) in rates of cannabis-attributable visits and the proportion of all-cause ED visits attributable to cannabis, respectively, with insignificant increases in monthly slopes. Similar patterns were observed in young adults. CONCLUSIONS: In Ontario, Canada, cannabis-attributable emergency department visits stopped increasing over time following recreational cannabis legalization with strict retail controls but then increased during a period coinciding with cannabis commercialization and the COVID-19 pandemic.

Israeli news media coverage of COVID-19 and use of cannabis and tobacco: A case study of inconsistent risk communication.

BACKGROUND: There is continued scientific debate regarding the link between risk of COVID-19 infection and increased disease severity and tobacco and cannabis use. The way this topic is presented in news media coverage may influence public attitudes and behavior and is thus an important topic of investigation. This study examines (1) the extent to which Israeli news media reported a positive (i.e., protective/therapeutic), negative (i.e., harmful), or inconclusive association between three types of substance use (tobacco, medical cannabis, recreational cannabis) and risk of COVID-19 infection and/or increased disease severity, and (2) the extent that this media coverage refers to scientific research. METHODS: A quantitative content analysis of news articles related to tobacco and cannabis use and COVID-19 (N = 113) from eleven of the highest circulation newspapers in Israel. RESULTS: News items were significantly more likely to mention increased COVID-19 risk for tobacco use, compared to cannabis use. All medical cannabis news items reported that medical cannabis use was associated with reduced COVID-19 risk. In contrast, news items about recreational cannabis use were more likely to describe a balanced or inconclusive risk for COVID-19, or increased risk. The majority of articles referred to scientific research. CONCLUSION: While Israeli news media reported a relatively consistent message about the increased risk of COVID-19 in relation to tobacco use, messages about cannabis use were less consistent in communicating risk information. Research should examine effects of media coverage of tobacco and cannabis use and COVID-19 on public perceptions and behaviors.

Clinical Relevance of Drug Interactions with Cannabis: A Systematic Review.

Concomitant use of cannabis with other drugs may lead to cannabis-drug interactions, mainly due to the pharmacokinetic mechanism involving the family of CYP450 isoenzymes. This narrative systematic review aimed to systematize the available information regarding clinical relevance of cannabis-drug interactions. We utilized the PubMed/Medline database for this systematic review, using the terms drug interactions and cannabis, between June 2011 and June 2021. Articles with cannabis-drug interactions in humans, in English or Spanish, with full-text access were selected. Two researchers evaluated the article's inclusion. The level of clinical relevance was determined according to the severity and probability of the interaction. Ninety-five articles were identified and twenty-six were included. Overall, 19 pairs of drug interactions with medicinal or recreational cannabis were identified in humans. According to severity and probability, 1, 2, 12, and 4 pairs of cannabis-drug interactions were classified at levels 1 (very high risk), 2 (high risk), 3 (medium risk), and 5 (without risk), respectively. Cannabis-warfarin was classified at level 1, and cannabis-buprenorphine and tacrolimus at level 2. This review provides evidence for both the low probability of the occurrence of clinically relevant drug interactions and the lack of evidence regarding cannabis-drug interactions.