Assessing the public health impact of cannabis legalization in Canada: core outcome indicators towards an ‘index’ for monitoring and evaluation

Abstract

The legalization of non-medical cannabis use and supply is impending in Canada. This constitutes a major policy change with the declared objective of improving public health outcomes, which requires rigorous monitoring and evaluation. While numerous different aspects associated with legalization will be examined, a focused perspective is required for effective policy evaluation purposes. To these ends, we have identified a set of 10 core indicators associated with cannabis-related risk/harm outcomes-based on current best evidence-that are expected to measure the primary impacts of legalization on public health outcomes. We briefly review these indicators, and their respective data availability in Canada. As ideally an integrated outcome assessment of cannabis legalization's impact on public health will be available, we further propose options to merge the individual indicators into an integrated, weighted 'index', considering their expected relative impact for public health. One possible approach to undertake this is 'multi-criteria decision analysis' as a method to weight the relative indicator impact on public health; alternative approaches are proposed. The integrated 'public health index' for cannabis legalization will allow for scientifically comprehensive, while focused, monitoring and evaluation of the effects of legalization in Canada for the benefits of science and evidence-based policy alike.

Guidelines for public health and safety metrics to evaluate the potential harms and benefits of cannabis regulation in Canada

“…Following the recommendations of Fischer et al . , researchers may want to apply a weighting system to create a combined weighted index of the overall public health impact (i.e. all 28 indicators) or for the impact under each theme.…”

“…The public health impact of cannabis legalisation will not be equally distributed across these 28 indicators; over time, certain indicators are likely to emerge as immediate and persistent priorities while others may lose relevance. Following the recommendations of Fischer et al [87], researchers may want to apply a weighting system to create a combined weighted index of the overall public health impact (i.e. all 28 indicators) or for the impact under each theme.…”

Assessing the public health impacts of legalizing recreational cannabis use: the US experience

“…We summarize here the adverse effects that may increase if harmful patterns of cannabis use, especially daily use, increase as a result of legalization. The content is based on reviews of the evidence on the adverse health effects of cannabis 35‐37 and analyses of health outcomes that should be monitored after cannabis legalization 38‐40 .…”

“…Relationships between cannabis use and the use of alcohol, tobacco and opioids will substantially affect the public health impacts of cannabis legalization 38,40,42 . The public health burdens of these drugs could be reduced if cannabis becomes a substitute, while their impact could be amplified if there is more concurrent use of cannabis and these drugs 38,40 .…”

Considering the health and social welfare impacts of non‐medical cannabis legalization

“…First, effects observed to date may be driven by “strawfire” (or “novelty”) dynamics. Second, the full public health impact of cannabis legalization will likely hinge on a combination of outcomes, including use prevalence and initiation among youth; high‐risk use patterns (such as frequent and/or high‐tetrahydrocannabinol use); cannabis‐impaired driving and consequent motor vehicle crashes and related injuries; use disorders and related treatment needs; hospitalizations for cannabis‐related problems; use substitution or interactions with alcohol, tobacco or other psychotropics 2 .…”