title: Burden of illness in idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  Idiopathic pulmonary fibrosis is a life-threatening condition, and few data concerning the impact on healthcare utilization and associated costs are available. The objective of this study was to describe the burden of illness (comorbidity, healthcare resource utilization, and associated costs) in patients with idiopathic pulmonary fibrosis.
  
  
  METHODS
  Two cohorts (patients with idiopathic pulmonary fibrosis and matched controls) were retrospectively identified from US claims databases between January 1, 2001 and September 30, 2008. Cases with idiopathic pulmonary fibrosis were defined by age of 55 years or older and either two or more claims with a code for idiopathic fibrosing alveolitis (ICD-9 516.3), or one claim with ICD 516.3 and a subsequent claim with a code for post-inflammatory pulmonary fibrosis (ICD-9 515). The prevalence and incidence of pre-selected comorbidities, healthcare resource utilization (hospital, outpatient, drugs), and direct medical costs were assessed in each cohort.
  
  
  RESULTS
  A total of 9286 patients with idiopathic pulmonary fibrosis were identified. When compared with age- and gender-matched controls, these patients were at significantly increased risk for comorbidities including pulmonary hypertension and emphysema. The all-cause hospital admission rate (0.5 per person-year) and the all-cause outpatient visit rate (28.0 per person-year) were both ∼2-fold higher than in controls. Total direct costs for patients with idiopathic pulmonary fibrosis were $26,378 per person-year; the incremental costs over controls were $12,124 (2008 value).
  
  
  CONCLUSIONS
  Patients with idiopathic pulmonary fibrosis experience increased comorbidity, healthcare resource utilization, and direct medical costs compared to controls.
authors.affiliation: University of California San Francisco, San Francisco, CA, USA.
authors.forename: Harold R
authors.initials: HR
authors.lastname: Collard
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Ward
authors.forename: Stephan
authors.initials: S
authors.lastname: Lanes
authors.forename: D
authors.initials: D
authors.lastname: Cortney Hayflinger
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Rosenberg
authors.forename: Elke
authors.initials: E
authors.lastname: Hunsche
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D017281:Cost of Illness; D016208:Databases, Factual; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data; D006295:Health Resources / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000191:economics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D014481:United States / Q000453:epidemiology