Characteristics of bronchiectasis in Korea: First data from the Korean Multicentre Bronchiectasis Audit and Research Collaboration registry and comparison with other international registries

Abstract

Understanding the aetiology and characteristics of patients with bronchiectasis is vital for developing strategies to reduce the burden of disease; however, geographical variations in these characteristics, which may have important implications for diagnosis and treatment,1, 2 make it difficult to formulate a uniform strategy for investigation. Here, we describe the burden of illness and treatment among Korean bronchiectasis patients and compare the results with those from three geographically and ethnically diverse regions: Australia, Europe and India. The Korean Multicentre Bronchiectasis Audit and Research Collaboration (KMBARC) is a prospective, non-interventional observational study.3 Data were collected from 598 patients enrolled in the KMBARC registry between August 2018 and December 2019. The KMBARC registry design and data collection fields are closely aligned with those used by other registries. Detailed information on bronchiectasis cohorts in Australia (n = 653), Europe (n = 2596) and India (n = 2195) has been previously described.1, 2, 4 Most patients in all cohorts were aged >60 years and predominantly females; however, Indian patients were nearly 10 years younger on average and predominantly males. The BMI was lower in Koreans and Indians than in Australians and Europeans. Regarding comorbidities, Korean patients showed a lower prevalence of ischaemic heart disease and a higher prevalence of chronic obstructive pulmonary disease than those in other bronchiectasis registries. The prevalence of asthma in Korean patients was comparable with that in Indians, but it was relatively lower in Australians and Europeans (Table 1). The bronchiectasis severity index of Koreans (median 6) was comparable with that of Europeans (median 6) and Indians (median 7). However, the bronchiectasis severity index of Australians (median 9) was relatively higher than that recorded in other registries. The rate of experiencing more than one hospital admission in the previous year was highest for Indians (38.8%), followed by Australians (30.5%), Europeans (25.9%) and Koreans (18.2%). Regarding pulmonary function, Australians had the highest forced expiratory volume in 1 s (% predicted) (median 79.4), followed by Europeans (median 73.8), Koreans (median 65.4) and Indians (median 61.4). Pseudomonas aeruginosa was the most common causative pathogen among Koreans, Australians and Indians, whereas Haemophilus influenzae was the most common in Europeans (Table 1). The two most common causes of bronchiectasis were idiopathic and tuberculosis (TB) in Koreans. In comparison, the two most common causes of bronchiectasis in the Australian and European registries were idiopathic and post-infective, whereas in the Indian registry, the most common causes were TB and post-infective. The rate of prescribing long-term antibiotics was highest in Australians (31.4%), followed by Europeans (19.4%), Indians (12.3%) and Koreans (3.9%) (Table 1). In conclusion, there were significant differences in the aetiology, comorbidities and treatment of bronchiectasis among the different countries and regions. Thus, we believe that the clinical guidelines for bronchiectasis in individual countries need to address these issues based on epidemiological data because they may vary from country to country. The authors thank all members of the Australian (Australian Bronchiectasis Registry), European (EMBARC), Indian (EMBARC-India) and Korean (KMBARC) registries. Hyun Lee: Conceptualization; data curation; formal analysis; investigation; writing-original draft; writing-review & editing. Hayoung Choi: Conceptualization; data curation; formal analysis; investigation; writing-original draft; writing-review & editing. James D Chalmers: Conceptualization; investigation; methodology. Raja Dhar: Conceptualization; investigation; methodology; writing-original draft; writing-review & editing. Tu Q Nguyen: Data curation; formal analysis; writing-original draft; writing-review & editing. Simone K Visser: Formal analysis; writing-original draft; writing-review & editing. Lucy C Morgan: Conceptualization; investigation; methodology; writing-original draft; writing-review & editing. Yeon-Mok Oh: Conceptualization; investigation; methodology; supervision; writing-original draft; writing-review & editing. The authors acknowledge funding support to the Australian Bronchiectasis Registry provided by Insmed, Zambon and philanthropic donations. These sponsors had no input to the interpretation of data or preparation of the manuscript. The authors declare that they have no other conflicts of interest.