title: Cannabis Abuse Is Increasing and Associated with Increased Emergency Department Utilization in Gastroenterology Patients.
abstract: The role of cannabinoids in gastrointestinal diseases is controversial and of great interest, yet their use in patients has not been critically examined.
  
  
  
  To determine the prevalence and effects of cannabis abuse on healthcare utilization, as measured by emergency department (ED) visits, in a large, tertiary gastroenterology practice.
  
  
  
  All patients seen in the gastroenterology clinic at a tertiary care center during a 27-year period (1986-2013) were included in our study to determine the overall prevalence of cannabis abuse. We matched cannabis abusers 1:2 with non-abusing controls to determine the effect of cannabis on ED utilization, our primary outcome. We used multivariate linear regression to adjust for confounders and define the independent effect of cannabis abuse on ED utilization.
  
  
  
  Our prevalence study cohort included 190,303 GI clinic patients with an overall cannabis abuse prevalence of 0.80 % (1520 patients). From 1986 to 2012, the prevalence of cannabis abuse in this clinic increased by 0.73 % (0.03 %/year) (p < 0.0001). From the 1520 cannabis abusers identified, 467 patients were randomly selected as cases and were matched to 934 controls. From this retrospective cohort, the median ED visits/year for cannabis abusers was 1.88 versus 0.89 for non-abusers (p < 0.0001). After multivariate adjustment, cannabis abuse was associated with a 1.47-fold increase (95 % CI 1.23-1.76, p < 0.0001) in median ED visits/year.
  
  
  
  Reported cannabis abuse in GI clinic patients is less prevalent than in the adult US population, but is increasing. Cannabis abuse among gastroenterology patients is associated with increased ED visits.
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA. jgubatan@bidmc.harvard.edu.
authors.forename: John
authors.initials: J
authors.lastname: Gubatan
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Staller
authors.affiliation: Pritzker School of Medicine, University of Chicago, Chicago, IL, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Barshop
authors.affiliation: Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Braden
authors.initials: B
authors.lastname: Kuo
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications*; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States
keywords: Cannabinoids; Cannabis; Epidemiology; Functional GI disorders; Healthcare utilization; Medical marijuana