Medication use and indicators of poor asthma control in patients with and without allergies.

Approximately two-thirds of people with asthma have some evidence of allergy; their condition differs from nonallergic asthma in terms of predominant symptoms and clinical outcomes. To compare asthma control and medication use among patients with persistent asthma with evidence of allergy (PA-EA) and patients with persistent asthma with no evidence of allergy (PA-NEA). A retrospective analysis of survey responses and medication claims data from the Observational Study of Asthma Control and Outcomes study, a prospective survey linked to retrospective claims-based analysis of patients ages ≥ 12 years with persistent asthma in a U.S. health maintenance organization. Evidence of allergy was defined as both a positive response to a survey question about hay fever and/or seasonal allergies and one or more medical diagnostic codes for atopic conditions. Regression models were used to compare asthma control (Asthma Control Questionnaire [ACQ] scores) and asthma medication use between PA-EA and PA-NEA. Adjusted data showed that, versus the patients with PA-NEA (n = 312), patients with PA-EA (n = 971) had higher (worse) 5-item and 6-item ACQ (ACQ-5 and ACQ-6) scores (by 0.34 [95% confidence interval {CI}, 0.24-0.44]; and 0.31 [95% CI, 0.21-0.40], respectively), were more likely to have poorly controlled asthma (ACQ-5 score ≥ 1.5: odds ratio 3.37 [95% CI, 2.07-5.50]; ACQ-6 score ≥ 1.5: odds ratio 3.46 [95% CI, 2.13-5.62]) and less likely to have well-controlled asthma (ACQ-5 score ≤ 0.75: odds ratio 0.21 [95% CI, 0.13-0.34]; ACQ-6 score ≤ 0.75: odds ratio 0.21 [95% CI, 0.13-0.35]). Patients with PA-EA also had greater asthma medication use, most notably 2.5 times more prescriptions of high-dose inhaled corticosteroid in a 4-month period (95% CI, 1.21-5.16) and 16.15 times higher odds of chronic oral corticosteroid use (95% CI, 1.50-174.09) versus PA-NEA. The patients with PA-EA versus PA-NEA had worse asthma control and greater medication use. These patients may need more vigilant clinical oversight and treatment management to ensure adequate asthma control.