Real-world cohort study of adult and pediatric patients treated for hereditary angioedema in the United States

Background: There is limited real-world evidence on hereditary angioedema (HAE) patient characteristics and health-care resource utilization (HCRU); in addition, pediatric patients have been described in small cohorts. Objective: To describe patient characteristics, treatment patterns, and HCRU among adult and pediatric patients treated for HAE in a large U.S. cohort. Methods: This retrospective cohort study used an administrative claims data base (January 2006 to September 2015). Eligible patients with either ≥1 pharmacy claim for HAE-indicated therapies (C1 inhibitors, ecallantide, icatibant) or ≥2 medical claims with codes associated with HAE (per medical billing codes), and ≥1 claim for androgens, fresh frozen plasma, tranexamic acid, or ε-aminocaproic acid formed a “treated cohort.” Three nonexclusive treated cohorts were assessed: overall, pediatric, and HCRU (≥2 years of continuous enrollment during 2010‐2015). Results: Overall, 1429 patients received treatment (mean ± standard deviation [SD] age, 38.8 ±15.7 years; 62.4% female patients; mean ± SD Charlson Comorbidity Index of 1.4 ± 2.4). Common comorbidities were allergy or anaphylaxis (51.4%) and anxiety or depression (35.8%). Diagnoses indicative of HAE attacks included swelling and/or angioedema (78.5%), abdominal pain (55.6%), and asphyxiation (27.2%). Use of HAE-indicated medication rose between 2006 and 2015 to 81.8%, whereas androgen use declined (from 91.5% to 24.9%). Similar trends were observed in the pediatric treated cohort (n = 143). In the HCRU treated cohort (n = 538), HAE-related claims for emergency department and inpatient admissions were observed for 36.6% and 22.3% of patients, respectively. Conclusion: In a large U.S. cohort of adult and pediatric patients who received treatments indicated or used for HAE, common comorbidities and trends in resource use denoted the substantial burden of attacks, which reflected a continued need that recently approved long-term prophylactic treatments may help to address.