title: Analysis of National Trends in Admissions for Pulmonary Embolism.
abstract: Pulmonary embolism (PE) remains a significant cause of hospital admission and health-care costs. Estimates of PE incidence came from the 1990s, and data are limited to describe trends in hospital admissions for PE over the past decade.
  
  
  
  We analyzed Nationwide Inpatient Sample data from 1993 to 2012 to identify patients admitted with PE. We included admissions with International Classification of Diseases, 9th revision, codes listing PE as the principal diagnosis as well as admissions with PE listed secondary to principal diagnoses of respiratory failure or DVT. Massive PE was defined by mechanical ventilation, vasopressors, or nonseptic shock. Outcomes included hospital lengths of stay, adjusted charges, and all-cause hospital mortality. Linear regression was used to analyze changes over time.
  
  
  
  Admissions for PE increased from 23 per 100,000 in 1993 to 65 per 100,000 in 2012 (P < .001). The percent of admissions meeting criteria for massive PE decreased (5.3% to 4.4%, P = .002), but the absolute number of admissions for massive PE increased (from 1.5 to 2.8 per 100,000, P < .001). Median length of stay decreased from 8 (interquartile range [IQR], 6-11) to 4 (IQR, 3-6) days (P < .001). Adjusted hospital charges increased from $16,475 (IQR, $10,748-$26,211) in 1993 to $25,728 (IQR, $15,505-$44,493) in 2012 (P < .001). All-cause hospital mortality decreased from 7.1% to 3.2% (P < .001), but population-adjusted deaths during admission for PE increased from 1.6 to 2.1 per 100,000 (P < .001).
  
  
  
  Total admissions and hospital charges for PE have increased over the past two decades. However, the population-adjusted admission rate has increased disproportionately to the incidence of patients with severe PE. We hypothesize that these findings reflect a concerning national movement toward more admissions of less severe PE.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL. Electronic address: sean@northwestern.edu.
authors.forename: Sean B
authors.initials: SB
authors.lastname: Smith
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Geske
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Parul
authors.initials: P
authors.lastname: Kathuria
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Michael
authors.initials: M
authors.lastname: Cuttica
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Schimmel
authors.affiliation: Department of Emergency Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: D Mark
authors.initials: DM
authors.lastname: Courtney
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL; University of Western Australia, Perth, Australia.
authors.forename: Grant W
authors.initials: GW
authors.lastname: Waterer
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wunderink
mesh_terms: D000368:Aged; D005260:Female; D017048:Health Care Costs; D017052:Hospital Mortality / Q000639:trends; D006760:Hospitalization / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D007902:Length of Stay / Q000639:trends; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology
keywords: hospitalization; mortality; pulmonary embolism