title: Cyclic vomiting presentations following marijuana liberalization in Colorado.
abstract: OBJECTIVE
  Case reports have described a syndrome of cyclic vomiting associated with chronic marijuana use, termed cannabinoid hyperemesis syndrome. The primary objective was to determine the prevalence of patients presenting with cyclic vomiting before and after the liberalization of medical marijuana in Colorado in 2009. The secondary objective was to describe the odds of marijuana use among cyclic vomiting visits in these same time periods.
  
  
  METHODS
  This was a cross-sectional study of cyclic vomiting visits to the emergency department (ED) before and after marijuana liberalization. ED visits with International Classification of Diseases, ninth revision, coding for cyclic vomiting or that met diagnostic criteria for cyclic vomiting by the Rome III criteria were included.
  
  
  RESULTS
  The authors reviewed 2,574 visits and identified 36 patients diagnosed with cyclic vomiting over 128 visits. The prevalence of cyclic vomiting visits increased from 41 per 113,262 ED visits to 87 per 125,095 ED visits after marijuana liberalization, corresponding to a prevalence ratio of 1.92 (95% confidence interval [CI] = 1.33 to 2.79). Patients with cyclic vomiting in the postliberalization period were more likely to have marijuana use documented than patients in the preliberalization period (odds ratio = 3.59, 95% CI = 1.44 to 9.00).
  
  
  CONCLUSIONS
  The prevalence of cyclic vomiting presentations nearly doubled after the liberalization of medical marijuana. Patients presenting with cyclic vomiting in the postliberalization period were more likely to endorse marijuana use, although it is unclear whether this was secondary to increased marijuana use, more accurate marijuana reporting, or both.
authors.affiliation: Department of Emergency Medicine, Denver Health Medical Center, Denver, CO.
authors.forename: Howard S
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Emergency Medicine, Denver Health Medical Center, Denver, CO.
authors.forename: John D
authors.initials: JD
authors.lastname: Anderson
authors.affiliation: Department of Emergency Medicine, Denver Health Medical Center, Denver, CO.
authors.forename: Omeed
authors.initials: O
authors.lastname: Saghafi
authors.affiliation: Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, CO.|Rocky Mountain Poison & Drug Center, Denver, CO.
authors.forename: Kennon J
authors.initials: KJ
authors.lastname: Heard
authors.affiliation: Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, CO.|Rocky Mountain Poison & Drug Center, Denver, CO.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Monte
mesh_terms: D000328:Adult; D000367:Age Factors; D003120:Colorado; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D007880:Legislation, Drug / Q000706:statistics & numerical data*; D008297:Male; D002189:Marijuana Abuse / Q000150:complications*; D016017:Odds Ratio; D015995:Prevalence; D012189:Retrospective Studies; D012737:Sex Factors; D012959:Socioeconomic Factors; D013577:Syndrome; D014839:Vomiting / Q000453:epidemiology* / Q000209:etiology*