Colorado Cannabis Legalization and Its Effect on Emergency Care

Abstract

Colorado legalized the use of medical marijuana in 2000, although it was not truly commercialized in the state until the US attorney general ceased the prosecution of marijuana users and suppliers in 2009. The result was striking: from January 2009 to January 2011, the number of registered medical marijuana licenses in Colorado increased from 5,051 to 118,895 (Figure 1). Figure 1 Number of active marijuana licenses in Colorado. In 2012, Colorado voted to legalize recreational marijuana beginning in 2014, making it the first state alongside Washington to permit recreational use. Several other states have recently legalized the use of medical or recreational marijuana, with other states considering similar measures (Figure 2).1 Given this trend, emergency physicians in training will likely be confronted with increasing volumes of marijuana-related emergency department (ED) visits and may learn from Colorado’s recent experience with increased availability of marijuana products. Figure 2 Marijuana legalization by state (as of May 2015). THE EPIDEMIOLOGIC EFFECT OF LEGALIZATION Although the significant increase in medical marijuana registrations does not prove its increased use, this inference is supported by various survey data. According to the National Survey on Drug Use and Health, the percentage of young Coloradan adults aged 18 to 25 years reporting marijuana use within the past year increased significantly after medical marijuana legalization (35% in 2007 to 2008 versus 43% in 2010 to 2011). Simultaneously, the percentage of adults aged 26 years or older perceiving “great risk” to marijuana use significantly decreased, from 45% to 31%.2 Interstate comparisons also show a higher prevalence of marijuana use in states in which it has been legalized versus those in which it has not. According to National Survey on Drug Use and Health responses from 2011 to 2013, the prevalence of Coloradan adults endorsing marijuana use within the last month was 19% compared with a national prevalence of 12%.3 According to data from the National Epidemiologic Survey on Alcohol and Related Conditions, residents of states with medical marijuana legalization were twice as likely to endorse marijuana use compared with residents of states without legalized medical marijuana.4