Burden of illness of patients with allergic asthma versus non-allergic asthma

Objective: Allergic and non-allergic asthma share similar symptoms, but differ in that allergic asthma is triggered by inhaled allergens. This study compared healthcare resource utilization (HCRU) and costs between these groups using US employer-based claims data. Methods: Health insurance claims from Truven Marketscan database (2002Q1-2010Q2) were analyzed. Included patients had >= 2 asthma diagnoses and >= 1 year of eligibility prior to and following the date of first asthma diagnosis. Patients with >= 1 diagnosis for allergic asthma and >= 1 diagnosis for other allergic conditions formed the allergic asthma cohort whereas patients without any of these diagnoses formed the non-allergic asthma cohort. Allergic and non-allergic asthma patients were matched 1:1. HCRU and costs during the study period were compared between cohorts using incidence rate ratios (IRR) and bootstrap methods. Results: Sixty four thousand four hundred and seventy three allergic and non-allergic asthma patients were matched (mean age = 30; 57.1% female; mean CCI = 0.2), with 7.1% and 0.36% having received an allergy test during the baseline period, respectively. During the study period, allergic asthma patients had significantly more asthma-related pharmacy dispensings (IRR[95% CI] = 2.25[2.22-2.28], p<0.001) and asthma-related outpatient visits (IRR[95% CI] = 2.29[2.27-2.32], p<0.001). Allergic asthma patients incurred 39% greater per-patient-per-year all-cause costs (allergic: $4008; non-allergic: $2889, p<0.001) and 79% greater asthma-related costs (allergic: $1063; non-allergic: $592, p<0.001) than non-allergic asthma patients. Conclusions: These results indicate, even in a relatively healthy population, allergic asthma is associated with greater HCRU and costs. Guideline-recommended IgE allergy tests should be employed in distinguishing the two forms of asthma, to optimize patient management and reduce costs.