Real-world exacerbation rates in Japanese patients with COPD: results from the EXACOS observational cohort study

Background: Several small studies indicate that acute exacerbations of COPD (AECOPD) rates in Japan are low. Aim: To assess AECOPD rates in a real-world population of pts in Japan. Methods: Observational cohort study (EXACOS-Japan) of claims data from the Japan Medical Data Center® database. Pts were aged ≥40 y, with ≥365 days of enrolment prior to first COPD diagnosis (January 1 2010–June 30 2016) and treatment. Primary objective: to estimate the frequency and rate of overall, mod., and sev. AECOPD in pts in Japan; rates were also analyzed by prior exacerbations. Results: Data collection: January 1 2010–June 30 2017; primary analysis: 9938 pts. Mean (SD) age at diagnosis: 53.7 (8.9) y, 57.9% male, mean (SD) follow-up: 3.4 (1.8) y. Among pts without prior AECOPD, 58.7% had ≥1 AECOPD (any severity), 56.2% had ≥1 mod. AECOPD, and 6.5% had ≥1 sev. AECOPD during follow-up (Table). The rate of AECOPD (any severity, all pts) was 0.21/pt/y, with the highest rates observed for pts with 1 sev. or ≥2 mod. or sev. prior AECOPD events. Conclusion: In Japan, annual AECOPD rates varied based on AECOPD history. A substantial proportion of pts with AECOPD had no documented AECOPD history, highlighting the need to evaluate AECOPD risk in pts without previous events and optimize clinical management to improve reporting of AECOPD and monitor mild symptoms.