Burden of illness seen in hereditary angioedema in Japanese patients: Results from a patient reported outcome survey.

Hereditary angioedema (HAE) is a potentially life-threatening rare disease, which is mainly caused by the deficiency or dysfunction of C1-esterase inhibitor, and characterized by spontaneous, recurrent episodes of edema in various parts of the body including internal organs and the laryngeal area. Delayed diagnosis and treatment increase the burdens and risks of this condition. The current study aimed to understand the burden of illness for HAE patients in Japan before and after diagnosis through a patient reported outcome survey. A survey instrument was distributed to 121 adult patients with HAE by a patient organization via HAE treating physicians between July and November in 2016. Seventy patients (57.9%) returned the questionnaire. Patients reported high levels of medical resource utilization, including emergency procedures and services. Episodes of receiving laparotomy were somewhat less after diagnosis with HAE than before, but no apparent difference in episodes of tracheotomy between before and after the diagnosis. The economic burden, including direct and indirect medical costs, was highest before diagnosis, but still perceived as substantial after diagnosis. Patients reported disruption of work and school life, with 40% reporting that they miss 10 or more days from work or education per year. Sixty percent of patients reported that HAE affected their daily activities. We concluded that HAE is associated with considerable physical, social, economic and psycho-social burdens even after diagnosis, and that higher attack frequency is associated with a heavy disease burden for patients in Japan.