title: Utilization due to chronic obstructive pulmonary disease and its predictors: a study using the U.S. National Emergency Department Sample (NEDS).
abstract: BACKGROUND
  Previous studies of healthcare utilization for chronic obstructive pulmonary disease (COPD) have focused on time-trends in COPD visits or COPD treatments, or the effect of hospital volume on mortality. Few data are available regarding outcomes after an ED visit (and subsequent hospitalization) for COPD, which are both very common in patients with COPD. Our objective was to assess time-trends and predictors of emergency department and subsequent inpatient health care utilization and charges associated with COPD in the U.S.
  
  
  METHODS
  We used the 2009-12 U.S. Nationwide Emergency Department Sample (NEDS) to study the incidence of ED visits and subsequent hospitalizations with COPD as the primary diagnosis. We used the 2012 NEDS data to study key patient/hospital factors associated with outcomes, including charges, hospitalization and dischage from hospital to home.
  
  
  RESULTS
  ED visits for COPD as the primary diagnosis increased from 1.02 million in 2009 to 1.04 in 2010 to 1.10 million in 2012 (0.79-0.82 % of all ED visits); respective charges were $2.13, $2.32, and $3.09 billion. In 2012, mean ED charges/visit were $2,812, hospitalization charges/visit were $29,043 and the length of hospital stay was 4.3 days. 49 % were hospitalized after an ED visit. Older age, higher median income, metropolitan residence and comorbidities (diabetes, hypertension, HF, hyperlipidemia, CHD, renal failure and osteoarthritis) were associated with higher risk whereas male sex, Medicaid or self pay insurance status, hospital location in Midwest, South or West U.S. were associated with lower risk of hospitalization. 65.4 % of all patients hospitalized for COPD from ED were discharged home. Older age, comorbidities (diabetes, HF, CHD, renal failure, osteoarthritis) and metropolitan residence were associated with lower odds of discharge to home, whereas male sex, payer other than Medicare, Midwest, South or West U.S. hospital location were associated with higher odds.
  
  
  CONCLUSIONS
  Health care utilization and costs in patients with COPD are significant and increasing. COPD constitutes a major public health burden in the U.S. We identified risk factors for hospitalization, costs, and home discharge in patients with COPD that will allow future studies to investigate interventions to potentially reduce COPD-associated utilization.
authors.affiliation: Medicine Service, Birmingham VA Medical Center, Birmingham, AL, USA. Jasvinder.md@gmail.com.|Department of Medicine at School of Medicine, and Division of Epidemiology at School of Public Health, University of Alabama at Birmingham (UAB), Faculty Office Tower 805B, 510 20th Street S, Birmingham, AL, 35294, USA. Jasvinder.md@gmail.com.|Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA. Jasvinder.md@gmail.com.
authors.forename: Jasvinder A
authors.initials: JA
authors.lastname: Singh
authors.affiliation: Department of Medicine at School of Medicine, and Division of Epidemiology at School of Public Health, University of Alabama at Birmingham (UAB), Faculty Office Tower 805B, 510 20th Street S, Birmingham, AL, 35294, USA. yus@uab.edu.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Yu
mesh_terms: D000368:Aged; D017281:Cost of Illness; D004636:Emergency Service, Hospital / Q000191:economics* / Q000706:statistics & numerical data; D005249:Fees and Charges / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000191:economics* / Q000453:epidemiology*; D018570:Risk Assessment; D014481:United States / Q000453:epidemiology; D014600:Utilization Review