Higher Immunoglobulin E (IgE) Levels Are Associated with Greater Emergency Care and Other Healthcare Utilization Among Asthma Patients in a Real-World Data Setting

Rationale:

IgE is a marker of allergic status in asthma, but there has been limited evaluation of whether higher levels of IgE might reflect poorer health outcomes, especially in a real-world setting.  

Methods:

This cross-sectional analysis used data from claims and electronic medical records (01/01/2007 – 08/31/2013) on asthma patients enrolled for ≥1-year. Assessed outcomes included asthma-related healthcare usage (medications, office and emergency department [ED] visits, hospitalizations) and asthma exacerbations. Outcomes for high-IgE vs. low-IgE groups were compared using t-test or Chi-square tests as appropriate.  High IgE was defined as ≥75 IU/mL, based on prior research.

Results:

In the study population (n=652; mean age 52.4; 70.7% female), 286 (43.9%) patients had high-IgE at least once. High-IgE patients were more likely to have used allergen immunotherapy (18.2% vs. 10.9%; p=0.008), chronic oral corticosteroids (OCS) (33.6% vs. 26.0%; p=0.034), LABA (64.0% vs. 56.0%, p=0.040), and omalizumab (8.7% vs. 3.6%; p=0.005) and had received higher total annual prednisone-equivalent dose (mean 738 vs. 494 mg; p=0.013); high-dose ICS usage did not differ between the groups (36.7% vs. 35.5%, p=0.753).   

High- vs. low-IgE asthma patients used asthma-related healthcare resources at the following rates per 1,000 patient-years: office visits (2,197 vs. 1,575; p=0.008), ED visits (62 vs. 5; p=0.002), and hospitalizations (19 vs. 14; p=0.141).  Asthma exacerbation rates totaled 1,393 (high-IgE) vs. 987 (low-IgE) per 1,000 patient-years, p=0.144. 

Conclusions:

Patients with high-IgE levels had increased rates of healthcare use, including emergency care and medications such as chronic OCS, which providers seek to limit.