Pharmacoeconomic evaluation of COPD

Abstract

Study objectives: The clinical outcomes and health-care costs of a cohort of 413 patients with COPD are reported.

Design: This study was a retrospective pharmacoeconomic analysis.

Setting: University teaching hospital and affiliated clinics.

Patients: COPD patients with an FEV(1) < 65% of predicted and an FEV(1)/FVC ratio < 70% were eligible to be included in this analysis.

Interventions: Health-care resource utilization and costs were identified through chart review and were stratified according to the severity of COPD using the American Thoracic Society stages I, II, and III. The pharmacoeconomic analysis was a cost-of-illness evaluation that included the acquisition costs of initially prescribed pulmonary drugs, acquisition cost of pulmonary drugs added during the follow-up period, oxygen therapy, laboratory and diagnostic test costs, clinic visit costs, and emergency department and hospital costs.

Results: Total treatment cost was highly correlated with disease severity, with stage I COPD having the lowest cost ($1,681 per patient per year), stage III COPD having the highest cost ($10, 812 per patient per year), and stage II COPD having a cost intermediate to stage I and stage III ($5,037 per patient per year). With the exception of add-on drug acquisition cost, all cost variables were the highest in stage III COPD, the lowest in stage I COPD, and intermediate in stage II COPD. Hospitalization was the most important cost variable for all three stages of COPD severity. When stratified by both disease severity and initial bronchodilator drug selection, ipratropium alone in stage I COPD patients and the combination of ipratropium plus a ss-agonist (with or without steroid therapy) in stage II and stage III COPD patients had the lowest total costs. Reasons for the lower total cost of the ipratropium and ipratropium plus ss-agonist treatment groups included lower add-on drug costs, fewer diagnostic and laboratory tests, and a lower utilization rate for clinic visits, emergency department visits, and hospitalizations.

Conclusions: Our study demonstrates a strong correlation between disease severity and total treatment cost in COPD. In addition, the type of bronchodilator therapy impacts total cost in COPD. In stage I COPD, ipratropium alone had the lowest total cost, while in stage II and stage III COPD, a combination of ipratropium plus a ss-agonist had the lowest total cost. These data support the concept that adherence to published treatment guidelines will result in lower health-care costs due to COPD.