Burden of Asthma in Elderly Japanese Patients: Using Hospital-Based Administrative Claims Data.

INTRODUCTION Data are lacking on severe asthma burden in elderly people in Japan. We assessed the prevalence and clinical/economic burden of severe asthma and asthma-related hospitalizations in elderly and younger Japanese patients. METHODS This retrospective study analyzed outpatient claims data and inpatient hospital discharge records among patients aged ≥ 15 years with asthma (defined as ≥ 2 prescriptions of inhaled corticosteroids [ICS] or ICS/long-acting beta-agonists [LABA]) between 1 July 2014 and 30 June 2017. We analyzed the outpatient visit assessment population with severe asthma (≥ 240-day prescription of high-dose ICS and ≥ 90-day prescription of ≥ 1 additional controllers) and the asthma-related hospitalization population (≥ 1 hospital admission[S] with a primary diagnosis of asthma/status asthmaticus and use of systemic corticosteroids) over a 1-year observation period before the date of each patient's latest asthma prescription or asthma-related hospitalization within the study period. The primary outcome was the proportion of elderly (≥ 65 years) and younger (15-39 and 40-64 years) patients among the outpatient visit assessment population. Secondary outcomes included outpatient and inpatient characteristics, asthma-related healthcare resource utilization, and asthma-associated costs, by age group. RESULTS Of the outpatient visit assessment population (n = 35,742), 4211 had severe asthma, with the prevalence of 8.2%, 12.8%, and 12.4% for the 15-39, 40-64, and ≥ 65 years age groups, respectively. Elderly versus younger outpatients with severe asthma had higher cumulative oral corticosteroid doses. Among both outpatient visit assessment population and hospitalization assessment population, elderly versus younger outpatients with severe asthma or asthma-related hospitalizations had more comorbidities, required more biological, hematological, immunological, and microbiological tests, and incurred higher asthma-associated costs. CONCLUSIONS In addition to reaffirming the higher prevalence of severe asthma in Japanese patients ≥ 40 years versus those < 40 years of age, our results demonstrated higher clinical and economic burden in elderly versus younger patients.