Many people talk about the safety of marijuana. This study in the February 24, 2016 issue of NEJM explores ED Visits and compares those from Colorado vs those visiting. Because Colorado is one of the few states where there is complete legalization of marijuana, there are reports of marijuana tourism. This article explores the differences between those two groups and comments that Colorado are more likely to present with GI complaints likely marijiuana/cannibinoid hyperemesis syndrome versus visitors who are more likely to present with altered mental status. Given that medical licensed distribution of marijuana occurred in 2009 and full legalization in 2014, this is one of the first reports.
From the article
… conducted a cross-sectional study in the setting of an urban academic hospital in Aurora, Colorado, that has approximately 100,000 ED visits per year and compared the rates of ED visits with International Classification of Diseases, Ninth Revision (ICD-9), codes of cannabis use between out-of-state residents and Colorado residents from 2012 through 2014. …. The rates of visits with ICD-9 codes for cannabis use were adjusted for the volume of annual visits, and consecutive years were compared with the use of the two-sample z-test of proportions…….[At the study] institution, the rate of ED visits possibly related to cannabis use among out-of-state residents doubled from 85 per 10,000 visits in 2013 to 168 per 10,000 visits in 2014, which was the first year of retail marijuana sales (rate ratio, 1.98; P=0.001). Among Colorado residents, the rate of ED visits possibly related to cannabis use did not change significantly between 2013 and 2014 (106 per 10,000 visits in 2013 and 112 per 10,000 visits in 2014; rate ratio, 1.05; P=0.26). The rates did not change significantly between 2012 and 2013 among out-of-state residents or Colorado residents……. however, from 2012 to 2014, the statewide rate among out-of-state residents rose from 78 per 10,000 visits in 2012 to 112 per 10,000 visits in 2013 to 163 per 10,000 visits in 2014 (rate ratios, 1.44 [2012 to 2013] and 1.46 [2013 to 2014]; P<0.001 for both comparisons). Among Colorado residents, from 2011 to 2014, the rate of ED visits possibly related to cannabis use increased from 61 to 70 to 86 to 101, respectively, per 10,000 visits (rate ratios, 1.14 [2011 to 2012], 1.24 [2012 to 2013], and 1.17 [2013 to 2014]; P<0.001 for all comparisons).The flattening of the rates of ED visits possibly related to cannabis use among Colorado residents in an urban hospital (Figure 1AFIGURE 1Emergency Department (ED) Visits Possibly Related to Cannabis Use at an Urban Academic Hospital in Aurora, Colorado, and Statewide.) may represent a learning curve during the period when marijuana was potentially available to Colorado residents for medical use (medical marijuana period) but was largely inaccessible to out-of-state residents.2 It is possible that reporting bias in the era after legalization has confounded these findings; ….