Characterizing COPD Exacerbation Patterns in the VA Healthcare System

Lee TA, Bartle B, Weiss KB. Characterizing COPD Exacerbation Patterns in the VA Healthcare System. Poster session presented at: American Thoracic Society Annual International Conference; 2005 May 1; San Diego, CA.

Objectives:Chronic obstructive pulmonary disease (COPD) patients experience recurrent acute exacerbations. These events range from mild severity treated as an outpatient to severe events that require a hospitalization. The objective of this analysis was to encounter and pharmacy data to characterize COPD exacerbations in VA patients.Methods:We identified a cohort of patients with a COPD diagnosis in FY2000 and followed them through the end of FY2002 or until death. Exacerbations were defined as one of the following: 1) COPD-related hospitalization; 2) COPD-related ED visit; or 3) COPD-related outpatient visit with either an oral steroid or antibiotic dispensed within 5 days of the visit. Exacerbations were assumed to last for 30 days and any event occurring within 30 days of the index event was counted as part of that exacerbation. We characterized the types and rates of exacerbations over the follow-up period.Results:There were 198,891 patients included in the analysis with an average age of 67.5 years (SD = 10.1). During follow-up, the patients experienced 123,139 exacerbations by 93,640 persons (47.1%). The annual average exacerbation was 0.336 (95% CI, 0.334 to 0.338) during follow-up. For those experiencing an exacerbation, the number of exacerbations during the follow-up period ranged from 1 to 15 exacerbations. A total of 53.0% of the exacerbations began as a hospitalization. Exacerbations were associated with an average of 1.48 healthcare contacts (SD = 0.81). The risk of having an exacerbation in the follow-up period increased as the number of exacerbations in the baseline period increased relative to those that did not have an exacerbation (1 exacerbation, OR = 1.85; 2 exacerbations, OR = 2.71; 3+ exacerbations, OR = 3.86).Implications:In a cohort of patients with COPD, nearly half of the patients experienced at least one exacerbation over the follow-up period. Patients with higher numbers of exacerbations in the baseline period had an increased risk of exacerbations in the follow-up.Impacts:As expected, acute exacerbations are a relatively frequent event in VA patients with COPD. Because the number of exacerbations in a year are associated with subsequent exacerbation risk, targeting individuals with high exacerbation rates may help identify sub-populations of COPD patients for special interventions.