title: Impact of COPD Exacerbation Frequency on Costs for a Managed Care Population.
abstract: BACKGROUND
  There is scarce information on chronic obstructive pulmonary disease (COPD) outcomes and costs for patients with differing levels of COPD exacerbations.
  
  
  OBJECTIVE
  To examine COPD-related and all-cause health care resource use and costs in subsequent years for frequently and infrequently exacerbating COPD patients.
  
  
  METHODS
  Patients with a diagnosis of COPD (ICD-9-CM codes 491.xx, 492.xx, and 496.xx) were identified (1 hospitalization or 1 emergency department visit or at least 2 outpatient visits) using administrative claims data in 2007. Patients were classified in 2008 as frequent (at least 2 exacerbations/year), infrequent (1 exacerbation/year) and nonexacerbators. Outcomes were computed during a subsequent 2-year period (2009 and 2010). Average per person estimates and total sample-level estimates were calculated. A logistic regression model estimated the predictors of having 2 or more exacerbations per year during the follow-up period.
  
  
  RESULTS
  61,750 COPD patients met the study criteria (mean age 67 years). Of these, 6% (n = 3,852) were frequent exacerbators; 14% were infrequent exacerbators (n = 8,416); and 80% were nonexacerbators (n = 49,482). At baseline, average all-cause health care costs per patient for frequent exacerbators were highest followed by infrequent and nonexacerbators ($12,837, $10,480, and $7,756, respectively). On average, 60% of frequent and 40% of infrequent exacerbators had at least 1 exacerbation per year in follow-up. Average annual per patient COPD-related costs for frequent exacerbators ($3,565 in 2009 and $3,528 in 2010) were more than 3 times (P  less than  0.05) and infrequent exacerbators ($2,264 in 2009 and $2,265 in 2010) were more than 2 times (P  less than  0.05) higher compared with nonexacerbators ($1,007 in 2009 and $1,027 in 2010). On a total sample-level, infrequent exacerbators were similar if not more burdensome compared with frequent exacerbators in the proportion accounted by these cohorts for total COPD-related costs (23% vs. 18%, respectively) and total number of COPD exacerbations per year (26% vs. 26%). Compared with nonexacerbators, infrequent exacerbators were 3 times (OR = 2.8, P  less than  0.001) significantly more likely to have 2 or more exacerbations per year in follow-up, and frequent exacerbators were 7 times (OR = 6.76, P  less than  0.001) significantly more likely to have 2 or more exacerbations per year in follow-up.
  
  
  CONCLUSIONS
  Infrequent exacerbators have an increased risk for future exacerbations compared with nonexacerbators and, on a total sample-level, incur greater costs compared with frequent exacerbators, demonstrating a significant economic burden.
authors.affiliation: GlaxoSmithKline, 5 Moore Dr., B.3130, Durham, NC 27709. anand.a.dalal @gsk.com.
authors.forename: Anand A
authors.initials: AA
authors.lastname: Dalal
authors.forename: Jeetvan
authors.initials: J
authors.lastname: Patel
authors.forename: Anna
authors.initials: A
authors.lastname: D'Souza
authors.forename: Eileen
authors.initials: E
authors.lastname: Farrelly
authors.forename: Saurabh
authors.initials: S
authors.lastname: Nagar
authors.forename: Manan
authors.initials: M
authors.lastname: Shah
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008329:Managed Care Programs / Q000191:economics*; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000191:economics* / Q000503:physiopathology; D012189:Retrospective Studies