Effect of Combination Fluticasone Propionate and Salmeterol or Inhaled Corticosteroids on Asthma-Related Outcomes in a Medicare-Eligible Population

Abstract

Background

National asthma treatment guidelines recommend either the use of inhaled corticosteroids (ICS) or ICS in combination with a long-acting bronchodilator for the treatment of moderate to severe asthma. Even though asthma is common among older adults, few studies have assessed the differences in effectiveness between these two recommended therapies in patients over 65 years of age.

Objective

The aim of this study was to assess the association of the fluticasone-salmeterol combination (FSC) or ICS initiation on asthma-related events in Medicare-eligible asthma patients.

Methods

This was a retrospective observational study using a large health claims database (July 1, 2001 to June 30, 2008). Subjects 65 to 79 years of age with 12-month preindex and 3- to 12-month postindex eligibility, an asthma diagnosis (ICD-493.xx), and with 1 or more FSC or ICS claims at index were included. Subjects with an FSC or ICS claim in the preindex and any claim for chronic obstructive pulmonary disease were excluded. Subjects were observed until they had an event (emergency department [ED] inpatient hospitalization [IP], combined IP/ED or oral corticosteroid [OCS] use) or were no longer eligible in the database, whichever came first. Cox proportional hazards regression was used to assess risk of an asthma-related event (IP, ED, or IP/ED). Baseline characteristics (age, sex, region, index season, comorbidities, preindex use of short-acting β-agonists, OCS, other asthma controllers, and asthma-related ED/IP visits) were independent covariates in the model.

Results

A total of 10,837 met the criteria (4843 ICS and 5994 FSC). Age (70.4 and 70.5 years, respectively) and the percentage of female subjects (65.5% and 64.8%, respectively) were similar. Asthma-related events were also similar at baseline. Postindex unadjusted rates occurring after >30 days were ED (1.8% vs 1.5%, P = 0.18), IP (2.7% vs 1.7%, P < 0.001), and ED/IP (4.1% vs 2.8%, P < 0.001) for ICS and FSC, respectively. Subjects who received FSC were associated with a 32% (adjusted HR = 0.68; 95% CI, 0.51–0.91) lower risk of experiencing an IP visit and a 22% (HR = 0.78; 95% CI, 0.62–0.98) lower risk of experiencing an ED/IP visit. No differences were observed for ED visits (HR = 0.94; 95% CI, 0.68–1.29).

Conclusions

In Medicare-eligible asthma patients, FSC use was associated with lower rates of asthma-related serious exacerbations compared with ICS.