In October 2013, Colorado voters approved amendment 64, legalizing recreational use of marijuana. In the subsequent Senate Bill 13-283, legislators passed important statutory changes necessary to implement the amendment. This bill included instruction that the Colorado Department of Public Health and Environment (CDPHE) “appoint a panel of health care professionals with expertise in cannabinoid physiology” to monitor emerging science relevant to the health effects of marijuana. The panel would provide a report every two years, beginning in January, 2015. CDPHE recruited thirteen initial members, and the group decided to be called the “Colorado Retail Marijuana Public Health Advisory Committee.”
METHODS:
Prior to the first Advisory Committee meeting, CDPHE began work internally to frame topic areas, gather existing research, and develop a rigorous, unbiased process for the literature review. The Committee refined and approved the topic areas and review process. The review process begins with a thorough search for all articles relevant to the topic area, using research databases and manual review of bibliographies. Articles are sifted to select those with findings on possible health effects from marijuana use. These are reviewed using criteria from established systematic review processes such as GRADE and MOOSE to identify strengths and limitations, as well as to characterize the population, exposure and outcome as clearly as possible. Findings are then grouped according to population, exposure and outcome. For each such group, the quality of each individual finding is rated high, medium or low quality, and the body of evidence as a whole is deemed substantial, moderate, limited, etc. This leads to an evidence summary statement, and major findings are translated into public health statements.
RESULTS:
Thousands of studies were considered and hundreds were included in reviews for the 2014 report. In that report, the Advisory Committee made 19 ‘substantial evidence’ statements, 18 ‘moderate evidence’ statements, 45 public health statements, 24 surveillance recommendations, 20 education recommendations, and identified 43 research gaps.
CONCLUSIONS:
The Advisory Committee’s work has strongly contributed to respectful and well-informed discussion in Colorado and nationally about the intersection of legalized marijuana and public health. CDPHE’s Environmental Epidemiology Branch and Preventive Services Division are working to implement their surveillance and education recommendations respectively. The research gaps they’ve identified may encourage and guide further marijuana research grant funding. Going forward, they continue to review emerging research, update previous topics and add new topics for the upcoming 2016 report.