COPD exacerbation frequency and its association with health care resource utilization and costs

Abstract

Background: Chronic obstructive pulmonary disease (COPD) exacerbations account for a substantial proportion of COPD-related costs.

Objective: To describe COPD exacerbation patterns and assess the association between exacerbation frequency and health care resource utilization (HCRU) and costs in patients with COPD in a Medicare population.

Methods: A retrospective cohort study utilizing data from a large US national health plan was conducted including patients with a COPD diagnosis during January 1, 2007 to December 31, 2012, aged 40-89 years and continuously enrolled in a Medicare Advantage Prescription Drug plan. Exacerbation frequency, HCRU, and costs were assessed during a 24-month period following the first COPD diagnosis (follow-up period). Four cohorts were created based on exacerbation frequency (zero, one, two, and ≥three). HCRU and costs were compared among the four cohorts using chi-square tests and analysis of variance, respectively. A trend analysis was performed to assess the association between exacerbation frequency and costs using generalized linear models.

Results: Of the included 52,459 patients, 44.3% had at least one exacerbation; 26.3%, 9.5%, and 8.5% had one, two, and ≥three exacerbations in the 24-month follow-up period, respectively. HCRU was significantly different among cohorts (all P<0.001). In patients with zero, one, two, and ≥three exacerbations, the percentages of patients experiencing all-cause hospitalizations were 49.7%, 66.4%, 69.7%, and 77.8%, respectively, and those experiencing COPD-related hospitalizations were 0%, 40.4%, 48.1%, and 60.5%, respectively. Mean all-cause total costs (medical and pharmacy) were more than twofold greater in patients with ≥three exacerbations compared to patients with zero exacerbations ($27,133 vs $56,033; P<0.001), whereas a greater than sevenfold difference was observed in mean COPD-related total costs ($1,605 vs $12,257; P<0.001).

Conclusion: COPD patients frequently experience exacerbations. Increasing exacerbation frequency is associated with a multiplicative increase in all-cause and COPD-related costs. This underscores the importance of identifying COPD patients at risk of having frequent exacerbations for appropriate disease management.

Keywords: COPD; costs; exacerbations; frequency.

Figure 1

Patient selection. Notes: ^aCOPD diagnosis: ≥2 medical claims occurring on separate dates within 90 days with a COPD diagnosis code (ICD-9-CM code 491.xx, 492.xx, or 496.xx) in the primary or secondary position; ^b≥1 medical claim with any of the following ICD-9-CM diagnosis codes in any position: 277.0x (cystic fibrosis), 011.x (pulmonary tuberculosis), or 140.xx–172.xx, 174.xx–209.3x, 209.7x (malignant neoplasms); ^cIndex date: the date of first medical claim with a COPD diagnosis during the identification period; ^dPreindex period: a 12-month period prior to index date; ^ePostindex period: a 24-month period after index date. Abbreviations: ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; MAPD, Medicare advantage plan with prescription drug benefits.

Figure 2

COPD-related health care costs by exacerbation frequency. Note: *Statistically significant (P<0.001) trend. Abbreviation: USD, United States dollar.

Figure 3

All-cause health care costs by exacerbation frequency. Note: *Statistically significant (P<001) trend. Abbreviation: USD, United States dollar.