A comparison of the risk of hospitalizations due to chronic obstructive pulmonary disease in medicaid patients with various medication regimens, including ipratropium, inhaled corticosteroids, salmeterol, or their combination

Abstract

Objective: The aim of this study was to compare therisk of hospitalizations related to chronic obstructive pulmonary disease (COPD) among Medicaid patients prescribed various medication regimens. Methods: This was an observational, retrospective study set in the Texas Medicaid program. Eligible patients were aged 40 to 65 years, had a primary or secondary diagnosis of COPD, and had ≥1 prescription for ipratropium (IPR), inhaled corticosteroids (ICS), or salmeterol (SAL) between January 1, 1998, and August 31, 2000. Five index therapy groups were included in the risk analysis: IPR alone, ICS alone, SAL alone, ICS + IPR, and ICS + SAL. Results: A total of 4447 patients were included in the study (IPR alone, n = 2435; ICS alone, n = 1088; SAL alone, n = 299; ICS + IPR, n = 410; and ICS + SAL, n = 215). After adjusting for baseline characteristics, ICS + SAL was associated with a 35% lower risk of COPD-related hospitalization (hazard ratio [HR], 0.653 [95% CI, 0.428–0.997]) versus IPR alone. ICS alone was associated with a 16% lower risk (HR, 0.844 [95% CI, 0.693–1.028]) and SAL alone was associated with a 24% lower risk (HR, 0.756 [95% CI, 0.539–1.060]) versus IPR alone, but neither of these was statistically significant. There was no decrease in risk with ICS + IPR versus IPR alone (HR, 1.111 [95% CI, 0.870–1.420]). Variables that indicated increased risk were as follows: increasing age (HR, 1.015 [95% CI, 1.003–1.027]); number of preindex emergency department visits (HR, 1.189 [95% CI, 1.080–1.309]); number of preindex hospitalization visits (HR, 1.342 [95% CI, 1.220–1.477] ); number of nonrespiratory comorbid diagnoses (HR, 1.046 [95% CI, 1.012–1.081]); and having a diagnosis of influenza/pneumonia (HR, 1.276 [95% CI, 1.062–1.533]) or other respiratory diseases (HR, 1.356 [95% CI, 1.134-1.622]). Comorbid asthma was not associated with increased risk. Conclusions: ICS + SAL was associated with a significantly lower risk of COPD-related hospitalization compared with IPR alone during the initial 12 months of therapy in a Medicaid population. Additional studies are needed to confirm these findings across different populations.