Establishing a hereditary angioedema prevalence for the United States using a large administrative claims database.

BACKGROUND

Hereditary angioedema (HAE) is a rare, potentially life-threatening genetic disorder. No US prevalence for all types of HAE has been estimated. Approval of 8 effective HAE therapies in the United States significantly expanded treated patient numbers and data collected in claims databases.

OBJECTIVE

To provide the first US prevalence estimate of HAE (all types) using claims-based insurance data.

METHODS

This retrospective study estimated the US prevalence of HAE using IQVIA's PharMetrics Plus MedTech claims database. Patients with 24 months of continuous database enrollment were divided into the following 3 cohorts: 2018, 2019, and 2020. Owing to the absence of International Classification of Diseases, Ninth Revision, Clinical Modification or International Classification of Diseases, 10th Revision, Clinical Modification diagnostic codes specific to HAE, we developed a proxy algorithm using International Classification of Diseases, 10th Revision, Clinical Modification codes for "angioneurotic edema" or "defects in the complement system" with more than or equal to 1 pharmacy claim for an HAE-indicated medication. An expert panel reviewed anonymized patient-level aggregate claims data to determine HAE status. A sensitivity analysis generated adjustment factors to address underrepresentation of Medicare patients in PharMetrics Plus MedTech database.

RESULTS

For 2018, 2019, and 2020, the claims-based algorithm yielded overall annual unadjusted HAE prevalence estimates per 100,000 and number of people diagnosed with HAE of 2.67, 9559; 2.61, 9341; and 2.43, 8694, respectively. The corresponding estimates based on expert physician analysis were 2.13, 7602; 2.03, 7275; and 1.84, 6595, respectively.

CONCLUSION

Our study provides the first claims-based comprehensive estimate of the US prevalence for all types of HAE across age groups, sexes, and geographic regions. Our calculations (which exceed the frequently cited 2:100,000 prevalence for HAE with C1 inhibitor deficiency) afford a real-world projected prevalence encompassing all types of HAE.