Impact of COPD Exacerbation Frequency on Costs for a Managed Care Population.

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.