Enhancing Methods for Research on Cannabis: A Workshop Report.

Aims: Progressive legalization of medical and recreational cannabis markets at the state-level has led to rapid growth of medical and recreational cannabis markets and to product diversification with emerging products having high concentrations of delta-9-tetrahydrocannabinol. Research on these products is still limited and the evidence available for policy formulation is diminished by methodological limitations.

Methods: As a step towards addressing these limitations, the Colorado School of Public Health convened a multidisciplinary workshop that addressed four areas of cannabis research: epidemiological, clinical, surveillance, and policy. Workshop participants provided recommendations in each area to advance research on cannabis to make it more informative for decision-making on key policy topics. Emphasis was placed on assessment of use of cannabis products by study participants.

Results: Recommendations for research methods and their implementation were made in the four areas. Those for epidemiology include using a core set of exposure assessment measures across three domains; developing this core set through a national and/or international scientific consensus process; ensuring the core set of measures are validated and readily available; and updating the core set periodically to account for ongoing changes in the cannabis landscape. Recommendations in the clinical research area include standard dosing and dosing terminology; standardized data collection instruments; identifying biomarkers for detecting cannabis exposure; and biological matrices. Policy research recommendations were offered for state regulators, evaluators/researchers, and policy makers. Surveillance recommendations include developing and implementing a novel and nimble surveillance system to monitor use of high-concentration forms of cannabis; adding questions to existing surveillance systems with the objective of monitoring high-concentration cannabis and adverse outcomes; and elevating the coordination, synthesis, and dissemination of findings in existing data sources that could signal adverse outcomes from high-concentration cannabis.

Conclusions: Given the changing marketplace, it is urgent to improve the informativeness of cannabis research through enhanced research methods.