Association between previous health care use and initiation of inhaled corticosteroid and long-acting beta2-adrenergic agonist combination therapy among US patients with asthma.

BACKGROUND

Combination inhaled corticosteroid and long-acting beta(2)-adrenergic agonist (ICS/LABA) therapy is recommended for patients whose asthma is not adequately controlled by other maintenance therapies and for those with moderate to severe asthma.

OBJECTIVES

This study examined the appropriateness of initiation of ICS/LABA combination therapy based on health care use criteria and the proportions of US patients filling prescriptions for either of 2 available therapies.

METHODS

This retrospective cohort study analyzed data from commercially insured asthma patients aged 12 to 64 years who initiated combination therapy with fluticasone propionate/salmeterol (FSC) or budesonide/ formoterol fumarate dihydrate (BFC) from July 1, 2007, to June 30, 2008. Continuously enrolled patients who had not received ICS/LABA therapy during a 12-month preindex period were assigned to the BFC or FSC cohort based on their initial ICS/LABA prescription (index date). Appropriate initiation of ICS/LABA combination therapy was determined based on the risks for asthma exacerbation, high impairment, and previous controller medication use. Specifically, initiation of ICS/LABA therapy was considered appropriate if patients had claims during the preindex period for an ICS or leukotriene receptor antagonist, an asthma-related emergency department visit or hospitalization, >or=2 courses of oral corticosteroid, or >or=6 canisters of a rescue short-acting beta(2)-adrenergic agonist (SABA). Factors associated with appropriate initiation of ICS/LABA therapy were assessed by multivariate logistic regression.

RESULTS

Of 16,205 patients initiated on ICS/LABA therapy, 39.2% met >or=1 criterion for appropriate use-788 of 1417 patients (55.6%) in the BFC group and 5572 of 14,788 patients (37.7%) in the FSC group (P < 0.001). Significantly greater proportions of BFC than FSC users met the individual criteria for previous controller medication use (45.7% vs 26.1%, respectively) and high SABA use (9.7% vs 6.1%). BFC users had a significantly higher likelihood of meeting >or=1 appropriateness criterion compared with FSC users (odds ratio = 1.79; 95% CI, 1.60-2.00; P < 0.001). Also significantly associated with appropriate use were receipt of the initial ICS/LABA prescription from a pulmonologist or allergist rather than from a physician in family medicine/general practice (P < 0.001), residence in the West relative to the Northeast (P < 0.005), and presence of specific comorbidities (allergic rhinitis, sinusitis, gastroesophageal reflux disease, and acute respiratory infection; all, P < 0.001).

CONCLUSIONS

Just under 40% of patients met the criteria for appropriate initiation of ICS/LABA therapy, with significantly greater proportions of BFC than FSC users meeting the overall and individual criteria for appropriate use. Patients with appropriate initiation of ICS/LABA therapy were significantly more likely to be treated by pulmonologists and allergists than by family medicine/general practitioners.