title: Hospital cost and length of stay in idiopathic pulmonary fibrosis.
abstract: OBJECTIVE
  To provide a detailed picture of the economic impact of hospitalization in idiopathic pulmonary fibrosis (IPF) and to identify factors associated with cost and length of stay (LOS).
  
  
  METHODS
  In this retrospective cross-sectional study using the Nationwide Inpatient Sample (NIS), this study included hospitalizations for IPF (ICD-9-CM 516.3) with a principal diagnosis of respiratory disease (ICD-9-CM 460-519) from 2009-2011; lung transplant admissions were excluded. Total inpatient cost, LOS, in-hospital death, and discharge disposition were reported. Linear regression models were used to determine variables predictive of LOS and cost.
  
  
  RESULTS
  From 2009-2011, 22,350 non-transplant IPF patients with a principal diagnosis of respiratory disease were admitted: mean (±SE) age was 70.0 (0.32), and 49.1% were female. While in hospital, 11.4% of patients received mechanical ventilation and 8.9% received non-invasive ventilation. Mean (±SE) LOS was 7.4 (0.15) days overall (p < .001). The mean (±SD) admission cost was $16,042 (±631). Of hospitalized patients, 14.1% died, 20.6% transferred facilities, and 46.4% were routinely discharged. The adjusted LOS (95% CI) for patients with and without mechanical ventilation was 16.1 days (15-17.5) vs. 6.3 (6-6.5); adjusted costs were $48,772 (43,979-53,565) vs. $11,861 (11,292-12,431).
  
  
  CONCLUSIONS
  The positive predictive value of the algorithm used to identify IPF is not optimal. The NIS database does not follow patients longitudinally, and claims after admission are not available. Claims do not indicate whether listed diagnoses were present on admission or developed during hospitalization. The exclusion of transplant-related expenditures lead to under-estimation of cost.
  
  
  CONCLUSIONS
  Using a nationally-representative database, we found IPF respiratory-related hospitalizations represent a significant economic burden with ∼7,000 non-transplant IPF admissions per year, at a mean cost of $16,000 per admission. Mechanical ventilation is associated with statistically significant increases in LOS and cost. Therapeutic advances that reduce rates and costs of IPF hospitalizations are needed.
authors.affiliation: a Department of Medicine , Stanford University , Stanford , CA , USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Mooney
authors.affiliation: b Genentech Inc. , South San Francisco , CA , USA.
authors.forename: Karina
authors.initials: K
authors.lastname: Raimundo
authors.affiliation: c Partnership for Health Analytic Research, LLC , Beverly Hills , CA , USA.
authors.forename: Eunice
authors.initials: E
authors.lastname: Chang
authors.affiliation: c Partnership for Health Analytic Research, LLC , Beverly Hills , CA , USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Broder
mesh_terms: D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D017722:Hospital Charges / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000191:economics* / Q000628:therapy; D007902:Length of Stay / Q000191:economics; D008297:Male; D010351:Patient Discharge / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012959:Socioeconomic Factors
keywords: Healthcare outcomes; cost of care; hospital database; insurance claims analysis; length of stay; mechanical ventilation; mortality; respiratory disease