Nationwide trends in pulmonary rehabilitation and clinical testing practices for chronic obstructive pulmonary disease in Korea: a National Health Insurance Service database study

Pulmonary rehabilitation (PR) is an evidence-based intervention for chronic obstructive pulmonary disease (COPD) and has been covered by Korea's National Health Insurance Service since 2016; however, national trends in PR use and related clinical testing have not been fully characterized. We conducted a nationwide retrospective cohort study using NHIS claims data from 2017 to 2021 among adults aged ≥40 years with COPD. Claim-defined comprehensive PR utilization was defined as at least one MM440 claim, while MM290 claims were analyzed separately. We performed 1:1 propensity score matching by age, sex, and region to compare PR recipients with non-recipients. The annual implementation rate of comprehensive PR (MM440) increased from 3.9 to 11.6 per 100,000 population, and the proportion of patients receiving PR rose from 0.49% in 2017 to 1.56% in 2021, while the mean number of PR claims per patient declined. In 2021, 94.8% of MM440 recipients had fewer than eight recorded MM440 claims. After matching, PR recipients had higher hospitalization rates, were more frequently treated in tertiary hospitals, and had higher malignancy-related claim counts and greater eligibility for co-payment reduction than non-recipients. The annual ratios of maximal inspiratory/expiratory pressure testing and cardiopulmonary exercise testing claims to MM440 claims were 11.2% and 7.0%, respectively, in 2021. In conclusion, although claim-defined PR utilization for COPD in Korea increased, overall uptake remained low, and the use of objective functional assessments was infrequent. These findings highlight persistent gaps in access and objective quality measurement and provide evidence to inform future PR implementation strategies in Korea.