@article{ref1,
title="Changes in medical cannabis use after recreational cannabis legalization in Canada",
journal="Cannabis and cannabinoid research",
year="2023",
author="Nguyen, Hai V. and Grootendorst, Paul and Mital, Shweta and Bishop, Lisa and McGinty, Emma E.",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="BACKGROUND: As part of its recreational cannabis legalization in October 2018, Canada imposed an excise tax of 10% (or $1 a gram, whichever is higher) on both recreational and medical cannabis. There is little evidence to inform the ongoing debate on whether the legalization had adverse impacts on medical cannabis use. <br><br>METHODS: We used an interrupted time series design and data on medical cannabis shipments (i.e., mail-order deliveries of cannabis from a licensed producer to a patient authorized to obtain medical cannabis) in Canada between quarter 1 of 2014 and quarter 1 of 2020. We examined changes in medical cannabis shipments after Canada's recreational cannabis legalization both across Canada and for each province. As this study used publicly available, province-level aggregate data, ethics approval was not required. <br><br>RESULTS: Recreational cannabis legalization was associated with significant reductions in medical cannabis use in 7 out of 10 Canadian provinces. Compared with the counterfactual estimated from prelegalization trends, the reduction in quarter 1 of 2020 varied from 500 shipments per 100,000 population (95% CI=312-688 shipments per 100,000 population) or 32% (95% CI=22-43%) in Newfoundland and Labrador to 3,778 shipments per 100,000 population (95% CI=2,972-4,585 shipments per 100,000 population) or 74% (95% CI=68-79%) in Alberta. At the national level, the number of medical cannabis shipments decreased by 823 per 100,000 population (95% CI=725-921 shipments per 100,000 population) or 48% (95% CI=45-52%). <br><br>CONCLUSIONS: Recreational cannabis legalization was associated with reductions in medical cannabis use. Our findings call for policy attention to address possible adverse impacts of recreational cannabis legalization on medical cannabis users.<p /> <p>Language: en</p>",
language="en",
issn="2578-5125",
doi="10.1089/can.2022.0227",
url="http://dx.doi.org/10.1089/can.2022.0227"
}