title: Trends in U.S. emergency department visits for opioid overdose, 1993-2010.
abstract: OBJECTIVE
  Emergency department (ED) visits for opioid overdose provide an important marker of acute morbidity. We sought to evaluate national trends of ED visits for opioid overdose.
  
  
  METHODS
  The National Hospital Ambulatory Medical Care Survey, 1993-2010, was used to identify ED visits for opioid overdose.
  
  
  METHODS
  Outcome measures were national ED visit rates for opioid overdose per 100,000 U.S. population and per 100,000 ED visits.
  
  
  RESULTS
  From 1993 to 2010, there were approximately 731,000 ED visits (95% CI, 586,000-877,000 visits) for opioid overdose, representing an overall rate of 14 ED visits (95% CI, 12-17 visits) per 100,000 population and 37 ED visits (95% CI, 31-45 visits) per 100,000 ED visits. Of these, 41% (95% CI, 33-50%) were for prescription opioid overdose. Between 1993 and 2010, the national visit rate increased from 7 to 27 per 100,000 population (+307%; Ptrend  = 0.03), and from 19 to 63 per 100,000 ED visits (+235%; Ptrend  < 0.001). Stratified analyses of the visit rate per population showed upward, but nonsignificant, trends across multiple demographic groups and U.S. regions. In stratified analyses of the visit rate per 100,000 ED visits, the rate increased significantly in several groups: age <20 years (+1188%; Ptrend  = 0.002), age 20-29 years (+155%; Ptrend  = 0.04), age ≥50 years (+231%; Ptrend  = 0.04), female (+234%; Ptrend  = 0.001), male (+80%; Ptrend  = 0.04), whites (+187%; Ptrend  < 0.001), and patients in the South (+371%; Ptrend  < 0.001).
  
  
  CONCLUSIONS
  In a nationally representative database of U.S. ED visits, we found that the ED visit rate for opioid overdose quadrupled from 1993 to 2010. Our findings suggest that previous prevention measures may not be adequate.
authors.affiliation: Department of Emergency Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Janice A
authors.initials: JA
authors.lastname: Espinola
authors.forename: David F M
authors.initials: DF
authors.lastname: Brown
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D062787:Drug Overdose / Q000453:epidemiology*; D004636:Emergency Service, Hospital / Q000639:trends*; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009293:Opioid-Related Disorders / Q000453:epidemiology*; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Emergency Department; Epidemiology; Opioids; Overdose; Time Trend