Epidemiology, burden, and policy of chronic obstructive pulmonary disease in South Korea: a narrative review

Survival benefit of inhaled corticosteroids in patients with chronic obstructive pulmonary disease: a nationwide cohort study

The role of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) is debated. We investigated whether the administration of ICS could lower the mortality risk in patients with COPD. We utilized the Korean National Health Insurance Service-National Sample Cohort database from 2002 to 2019. We included patients who had claim codes for COPD and inhalation respiratory medicine at least twice a year. A time-dependent Cox regression model was employed to estimate the association between ICS usage and survival. The cumulative dose of ICS was classified into three groups, and the mortality risk was compared among these groups. Of 16,463 included patients, there were 4395 (26.7%) deaths during the mean follow-up period of 5.0 years. The time-dependent Cox regression model demonstrated that ICS users had a significantly lower mortality risk compared to non-users (adjusted hazard ratio, 0.89; 95% CI, 0.83-0.94; p < 0.001), particularly among individuals aged ≥ 55 years, women, never smokers, and those with history of asthma or coronary heart disease. Higher cumulative dose groups were associated with a lower mortality risk compared to the lowest cumulative dose group. In conclusion, the administration of ICS seemed to be associated with a lower mortality risk in patients with COPD.

Clinical Characteristics and Frequency of Chronic Obstructive Pulmonary Disease Exacerbations in Korean Patients: Findings From the KOCOSS Cohort 2012-2021

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) exert a substantial burden on patients and healthcare systems; however, data related to the frequency of AECOPD in the Korean population are limited. Therefore, this study aimed to describe the frequency of severe, and moderate or severe AECOPD, as well as clinical and demographic characteristics of patients with chronic obstructive pulmonary disease (COPD) in South Korea.

METHODS

Data from patients aged > 40 years with post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity ≤ 70% of the normal predicted value from the Korea COPD Subgroup Study database were analyzed (April 2012 to 2021). The protocol was based on the EXAcerbations of COPD and their OutcomeS International study. Data were collected retrospectively for year 0 (0-12 months before study enrollment) based on patient recall, and prospectively during years 1, 2, and 3 (0-12, 13-24, and 25-36 months after study enrollment, respectively). The data were summarized using descriptive statistics.

RESULTS

Data from 3,477 Korean patients (mean age, 68.5 years) with COPD were analyzed. Overall, most patients were male (92.3%), former or current smokers (90.8%), had a modified Medical Research Council dyspnea scale score ≥ 1 (83.3%), and had moderate airflow limitation (54.4%). The mean body mass index (BMI) of the study population was 23.1 kg/m², and 27.6% were obese or overweight. Hypertension was the most common comorbidity (37.6%). The mean blood eosinophil count was 226.8 cells/μL, with 21.9% of patients having ≥ 300 cells/μL. A clinically insignificant change in FEV1 (+1.4%) was observed a year after enrollment. Overall, patients experienced a mean of 0.2 severe annual AECOPD and approximately 1.1 mean moderate or severe AECOPD. Notably, the rates of severe AECOPD remained generally consistent over time. Compared with patients with no exacerbations, patients who experienced severe exacerbations had a lower mean BMI (21.7 vs. 23.1 kg/m²; P < 0.001) and lower lung function parameters (all P values < 0.001), but reported high rates of depression (25.5% vs. 15.1%; P = 0.044) and anxiety (37.3% vs. 16.7%; P < 0.001) as a comorbidity.

CONCLUSION

Findings from this Korean cohort of patients with COPD indicated a high exacerbation burden, which may be attributable to the unique characteristics of the study population and suboptimal disease management. This highlights the need to align clinical practices with the latest treatment recommendations to alleviate AECOPD burden in Korea.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05750810.

Disease burden of COPD attributable to PM2.5 in China, Japan and South Korea from 1990 to 2019: a comparative study based on Global Burden of Disease Study 2019

OBJECTIVE

We hope to reveal the changing trends of chronic obstructive pulmonary disease (COPD) burden attributable to particulate matter pollution (PM2.5) and its age, period and cohort effects in China, Japan and Korea.

DESIGN

We analysed the trend of COPD disease burden attributable to PM2.5 from 1990 to 2019 based on the latest Global Burden of Disease Database (GBD 2019) using JoinPoint model and analysed the effect of age, period and cohort on COPD burden attributable to PM2.5 in China, Japan and Korea from 1990 to 2019 using age-period-cohort model (model).

SETTING

GBD data from 1990 to 2019.

PARTICIPANTS

Data were publicly available and individuals were not involved.

MAIN OUTCOMES

Outcomes included the age standardised mortality rate (ASMR), the age-standardised disability-adjusted life year (DALY), average annual per cent change (AAPC), net drift, local drift, longitudinal age curves, period (cohort) rate ratios, age (period, cohort) bias coefficient.

RESULTS

From 1990 to 2019, the ASMR of COPD attributable to PM2.5 in China (AAPC=-5.862), Japan (AAPC=-1.715) and Korea (AAPC=-1.831) showed a downward trend. The age-standardised DALY of COPD attributable to PM2.5 in China (AAPC=-5.821), Japan (AAPC=-1.39) and Korea (AAPC=-1.239) showed a downward trend. Mortality of COPD attributable to PM2.5 increased slowly with age in Korea and Japan. Mortality of COPD attributable to PM2.5 in China decreased after rising (95% CI: 404.66 to 466.01). Mortality of COPD attributable to PM2.5 decreased over time in China and Korea, while it increased in Japan from 2015 to 2019. In China and Japan, mortality of COPD attributable to PM2.5 was approximately lower the later the birth, while in Korea it decreased after an increase (95% CI: 2.13 to 2.40) in the 1900-1910.

CONCLUSIONS

Most COPD burden attributable to PM2.5 is on the decline; COPD mortality attributable to PM2.5 both increased with age and decreased with time and cohort. Countries with high burden should develop targeted measures to control PM2.5.

Clinical Efficacy of Mobile App-Based, Self-Directed Pulmonary Rehabilitation for Patients With Chronic Obstructive Pulmonary Disease: Systematic Review and Meta-Analysis

Background

Pulmonary rehabilitation is well known to improve clinical symptoms (including dyspnea), quality of life, and exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, researchers have reported difficulties in practicing center-based pulmonary rehabilitation. Recently, mobile app-based pulmonary rehabilitation has become available in clinical practice. We investigated the clinical outcomes of mobile app-based pulmonary rehabilitation in patients with COPD.

Objective

The objective of our study was to evaluate the clinical efficacy of mobile app-based pulmonary rehabilitation versus conventional center-based pulmonary rehabilitation for patients with COPD, using a systematic review and meta-analysis.

Methods

A systematic search of the literature published between January 2007 and June 2023 was performed, using the PubMed, Embase, Cochrane, and CINAHL databases to identify relevant randomized controlled trials involving patients with COPD. Pulmonary rehabilitation programs needed to provide an exercise program on a smartphone app. Study outcomes, including exercise capacity, symptom scores, quality of life, and hospitalization, were evaluated. The meta-analysis evaluated mean differences in 6-minute walk test distances (6MWDs), COPD Assessment Test (CAT) scores, modified Medical Research Council (mMRC) dyspnea scale scores, St. George Respiratory Questionnaire (SGRQ) scores, and risk ratios for hospitalization resulting from disease exacerbation.

Results

Of the 1173 screened studies, 10 were included in the systematic review and 9 were included in the meta-analysis. Further, 6 studies were multicenter studies. There were a total of 1050 participants, and most were aged ≥65 years. There were discrepancies in the baseline participant characteristics, smartphone apps, interventions, and study outcomes among the included studies. In the meta-analysis, 5 studies assessed 6MWDs (mean difference 9.52, 95% CI -3.05 to 22.08 m), 6 studies assessed CAT scores (mean difference -1.29, 95% CI -2.39 to -0.20), 3 studies assessed mMRC dyspnea scale scores (mean difference -0.08, 95% CI -0.29 to 0.13), 2 studies assessed SGRQ scores (mean difference -3.62, 95% CI -9.62 to 2.38), and 3 studies assessed hospitalization resulting from disease exacerbation (risk ratio 0.65, 95% CI 0.27-1.53). These clinical parameters generally favored mobile app-based pulmonary rehabilitation; however, a statistically significant difference was noted only for the CAT scores (P=.02).

Conclusions

Despite some discrepancies in the baseline participant characteristics and interventions among studies, mobile app-based pulmonary rehabilitation resulted in favorable exercise capacity, symptom score, quality of life, and hospitalization outcomes when compared with conventional pulmonary rehabilitation. In the meta-analysis, the CAT scores of the mobile app-based pulmonary rehabilitation group were significantly lower than those of the control group (P=.02). In real-world practice, mobile app-based pulmonary rehabilitation can be a useful treatment option when conventional center-based pulmonary rehabilitation is not feasible.

Incidence and Healthcare Burden of Pertussis among Older Adults with and without Pre-Existing Chronic Obstructive Pulmonary Disease or Asthma in South Korea

A retrospective cohort study was conducted to examine trends in the incidence and burden of pertussis among adults ≥50 years in South Korea, with/without pre-existing chronic obstructive pulmonary disease (COPD) or asthma. The nationwide Health Insurance Review and Assessment Service (HIRA) database was used to identify patients ≥50 years diagnosed with pertussis (2009-2018). Mean annual incidence of pertussis per 100 000 persons and overall mean incidence rate ratios (IRR) were calculated for patients with pre-existing COPD or asthma versus those with neither. Incremental healthcare costs (all-cause and pertussis-related) and healthcare utilisation (number of outpatient visits, emergency room visits, and number and length of hospitalisations) up to 12 months after, compared to 3 months before pertussis diagnosis, were also measured for each group (matched on sex, age, and Charlson Comorbidity Index). Of 1011 pertussis cases, 175 had asthma, 96 had COPD (not mutually exclusive), and 796 had neither. Overall mean pertussis incidence was 2.5, 3.4, and 0.5 for adults with pre-existing COPD, asthma, and those with neither. IRR (95% confidence interval) of pertussis for adults with pre-existing COPD and asthma was 4.9 (4.0-‍6.1) and 6.7 (5.7-7.9). Both COPD-pertussis and asthma-pertussis groups had higher mean incremental all-cause costs and length of hospitalisations than the general-pertussis group 3 months following pertussis diagnosis. In conclusion, individuals ≥50 years in South Korea with pre-existing COPD or asthma were at an increased risk of being diagnosed with pertussis and had higher healthcare resource utilisation than those without these conditions.

Sex differences in the impact of diabetes mellitus on tuberculosis recurrence: a retrospective national cohort study

OBJECTIVES

Whether diabetes mellitus (DM) increases tuberculosis (TB) recurrence risk is debatable. We determined the effect of DM on TB recurrence.

METHODS

This retrospective nationwide cohort study included patients with TB who successfully completed TB treatment during 2011-2017 and were followed up for TB recurrence until August 2020. We performed subdistribution hazard model analyses stratified by sex to assess DM risk related to TB recurrence after successful treatment.

RESULTS

Of 199,571 participants who had received successful TB treatment, 47,952 (24%) had DM. There were more men (64.4%), positive acid-fast bacilli smears (35.9%), and positive cultures (49.5%) in the DM group. There were 6208 (3.1%) TB recurrences during 5.1 years of follow-up: 38.9% and 26.6% occurred 1 and 1-2 years after treatment completion, respectively. The recurrence rate was higher in the DM group (3.8%) than in the non-DM group (2.9%, P <0.0001). DM was associated with a higher TB recurrence risk, especially in men (adjusted hazard ratio 1.23, 95% confidence interval 1.15-1.32) but not in women (adjusted hazard ratio 0.96, 95% confidence interval 0.85-1.09).

CONCLUSION

The TB recurrence rate after successful treatment was higher in patients with DM than in patients without DM. DM is associated with TB recurrence in men.

Global, regional and national burden of chronic obstructive pulmonary disease over a 30-year period: Estimates from the 1990 to 2019 Global Burden of Disease Study

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is the most prevalent chronic respiratory disease. This study investigated the global, regional and country burden of COPD based on gender, age and socio-demographic indices (SDIs) in the last 30-year period from 1990 to 2019.

METHODS

The COPD data, including incidence, mortality and disability-adjusted life years (DALYs), were obtained from the 2019 Global Burden of Disease Study. If age-standardized incidence rate (ASIR) or death rate (ASDR) remains almost constant or decreases, the number of cases will still increase as the global population increases substantially. Estimated annual percentage change (EAPC) was calculated to assess incidence, mortality and DALY trends.

RESULTS

The incidence of COPD increased by 85.89% from 8,722,966 cases in 1990 to 16,214,828 cases in 2019, and the ASIR decreased from 216.48/100,000 persons in 1990 (95%UI, 204.56-227.33) to 200.49 per 100,000 persons (95%UI, 188.63-212.57) in 2019. The ASIR increased (EAPC = 0.05, 95%CI, 0.01-0.10) in the low SDI region, was stable in the high SDI region, and fell in the other three SDI regions. Men had a higher ASIR than women over the past 30 years, and there were differences in the incidence rates for different age groups. Male mortality and DALYs were higher than female mortality. ASDR decreased by 2.13% (95%CI, -2.23% to -2.02%) per year and the annual age-standardized DALY rate decreased by 1.97% (95%CI, -2.05% to -1.89%).

CONCLUSIONS

The ASIR, ASDR and age-standardized DALY rate of COPD declined overall in the last 30 years, and were highest in the low-middle SDI region.