title: Scope of problem of pulmonary arterial hypertension.
abstract: BACKGROUND
  As with many uncommon diseases, data in patients with pulmonary arterial hypertension are sparse in regard to emergency service visits, hospitalizations, and mortality. The purpose of this investigation is to assess the scope of the problem of Group 1 pulmonary arterial hypertension in adults in the US and trends from 2001 to 2007.
  
  
  METHODS
  The Nationwide Emergency Department Sample, 2007-2011, was used to determine the number of emergency department visits, hospitalizations, and all-cause mortality of patients aged ≥18 years with Group 1 pulmonary arterial hypertension. We assessed patients with a discharge code for "primary pulmonary hypertension," and excluded patients with known causes of pulmonary hypertension that are not classified as Group 1.
  
  
  RESULTS
  There were 64,451 emergency department visits and 52,779 hospitalizations for pulmonary arterial hypertension from 2007-2011 in patients aged ≥18 years. The proportion of all emergency department visits that were for pulmonary arterial hypertension decreased from 16.4/100,000 visits in 2007 to 8.9/100,000 visits in 2011 (P < .0001). The proportion of all hospitalizations that were for pulmonary arterial hypertension decreased from 79/100,000 hospitalizations in 2007 to 38/100,000 hospitalizations in 2011 (P < .0001). Population-based death rates in patients with pulmonary arterial hypertension decreased from 4.6/million population in 2007 to 1.7/million population in 2011 (P < .0001).
  
  
  CONCLUSIONS
  Decreasing rates of emergency department visits, hospitalizations, and deaths in patients with Group 1 pulmonary arterial hypertension were shown from 2007-2011. We speculate that this resulted from improved treatment during the period of observation.
authors.affiliation: Department of Osteopathic Medical Specialties, Michigan State University College of Osteopathic Medicine, East Lansing. Electronic address: steinp@msu.edu.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Stein
authors.affiliation: Department of Osteopathic Medical Specialties, Michigan State University College of Osteopathic Medicine, East Lansing.
authors.forename: Fadi
authors.initials: F
authors.lastname: Matta
authors.affiliation: Department of Emergency Medicine, Summa Akron City Hospital, Akron, Ohio.
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Hughes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Emergency department; Hospitalizations; Mortality; Pulmonary hypertension