Assessing Treatment Effects of Inhaled Corticosteroids on Medical Expenses and Exacerbations Among COPD Patients: Longitudinal Analysis of Managed Care Claims

Objective: To assess costs, effectiveness, and cost-effectiveness of inhaled corticosteroids (ICS) augmenting bronchodilator treatment for chronic obstructive pulmonary disease (COPD).

Data Sources: Claims between 1997 and 2005 from a large managed care database.

Study Design: Individual-level, fixed-effects regression models estimated the effects of initiating ICS on medical expenses and likelihood of severe exacerbation. Bootstrapping provided estimates of the incremental cost per severe exacerbation avoided.

Data Extraction Methods: COPD patients aged 40 or older with > or = 15 months of continuous eligibility were identified. Monthly observations for 1 year before and up to 2 years following initiation of bronchodilators were constructed.

Principal Findings: ICS treatment reduced monthly risk of severe exacerbation by 25 percent. Total costs with ICS increased for 16 months, but declined thereafter. ICS use was cost saving 46 percent of the time, with an incremental cost-effectiveness ratio of $2,973 per exacerbation avoided; for patients > or = 50 years old, ICS was cost saving 57 percent of time.

Conclusions: ICS treatment reduces exacerbations, with an increase in total costs initially for the full sample. Compared with younger patients with COPD, patients aged 50 or older have reduced costs and improved outcomes. The estimated cost per severe exacerbation avoided, however, may be high for either group because of uncertainty as reflected by the large standard errors of the parameter estimates.