Prevalence, incidence, and mortality of nontuberculous mycobacterial infection in Korea: a nationwide population-based study.

BACKGROUND: Epidemiologic characteristics of nontuberculous mycobacterial (NTM) disease remain largely unknown. The objective of this study was to evaluate incidence, prevalence, and mortality of NTM infection in a large nationwide population-based cohort in Korea. METHODS: Data of the National Health Insurance Service database, an extensive health-related database including most Korean residents, were used. Adults with a primary diagnosis of NTM as determined by International Classification of Disease-Tenth Revision coding (A31) were identified between 2003 and 2016. Incidence, prevalence, and mortality of NTM infection were analyzed. RESULTS: A total of 46,194 individuals had a primary diagnosis of NTM infection. Their mean age was 55.8 years. Of these subjects, 61.1% were females. Annual age-adjusted incidence and prevalence of NTM infection tended to increase rapidly from 2003 to 2016. Age-adjusted incidence and prevalence was 17.9 and 33.3 per 100,000 population in 2016. The incidence and prevalence were higher in females and the elderly. The 5-year mortality rate in the population with NTM infection was 17.8%. The standardized mortality ratio of patients with NTM infection to the general population was 2.16 (95% confidence interval: 2.10 to 2.22). CONCLUSIONS: This large population-based study showed that the incidence and prevalence of NTM infection in Korea increased rapidly from 2003 to 2016. They were higher in women and the elderly. The mortality rate in the population with NTM infection was higher than that in the general population.

Body mass index as a predictor of mortality in bronchiectasis: A nationwide population-based study.

INTRODUCTION: The prognosis of bronchiectasis is not well known. The purpose of this study was to evaluate the association between body mass index (BMI) and mortality in bronchiectasis using a large nationwide population-based cohort. MATERIAL AND METHODS: Using the National Health Insurance Service-Health Screening Cohort in Korea, individuals with bronchiectasis were identified from 2004 to 2006 and monitored for up to 10 years. Mortality in bronchiectasis was analyzed based on a BMI score <18.5 kg/m2 (underweight), 1.85-22.9 kg/m2 (normal weight), 23.0-24.9 kg/m2 (overweight), and >25.0 kg/m2 (obese). RESULTS: A total of 2769 individuals with bronchiectasis were included. The underweight, normal weight, overweight, and obese accounted for 5.1%, 40.4%, 25.4%, and 29.3% of all patients with bronchiectasis, respectively. Compared to normal weight, underweight in bronchiectasis was associated with increased all-cause mortality (hazard ratio [HR] = 2.60; 95% confidence interval [CI] = 1.92-3.54), while obese was associated with decreased all-cause mortality (HR = 0.71; 95% CI = 0.55-0.93). This relationship between BMI and mortality was more prominent in respiratory disease-related mortality. CONCLUSIONS: BMI is a predictor of mortality in bronchiectasis. Underweight is associated with increased mortality among individuals with bronchiectasis while obese is associated with decreased mortality.

Prevalence, incidence, and mortality of sarcoidosis in Korea, 2003-2015: A nationwide population-based study.

BACKGROUND: The prevalence and incidence of sarcoidosis, a granulomatous disorder involving multiple organ systems, varies among geographical regions and ethnicities. This study evaluated the incidence, prevalence, and mortality of sarcoidosis in a large nationwide population-based cohort in Korea. METHODS: We used data of the National Health Insurance Service database, which is an extensive health-related database including most Korean residents. Adults with a primary diagnosis of sarcoidosis, as determined by International Classification of Disease-Tenth Revision coding (D86), were identified between 2003 and 2015. The incidence, prevalence, and mortality of sarcoidosis were analysed by sex and age. RESULTS: A total of 6376 individuals had a primary diagnosis of sarcoidosis. Their mean age was 48.8 years, and 58.6% were women. The age-adjusted incidence and prevalence of sarcoidosis were 1.3 and 3.4 per 100,000 population respectively; both tended to increase between 2003 and 2015. The all-cause mortality rate was 13.1 per 1000 sarcoidosis patients. The standardised mortality ratio of sarcoidosis patients to the general population was 1.7 (95% confidence interval, 1.5 to 1.8). CONCLUSIONS: This is the largest epidemiologic study of sarcoidosis in an Asian population to date. In Korea, the annual incidence and prevalence of sarcoidosis were relatively low but tended to increase over the 13 years of the study period. Importantly, the overall mortality rate of patients with sarcoidosis was higher than that of the general population.

Factors associated with the diagnostic yield of computed tomography-guided transbronchial lung biopsy.

BACKGROUND: Computed tomography (CT) may be useful for increasing the diagnostic yield of transbronchial lung biopsy (TBLB). However, only a few studies with small sample sizes have reported the diagnostic utility of CT-guided TBLB and the factors affecting the diagnostic accuracy of CT-guided TBLB are not well known. We evaluated the diagnostic yield of CT-guided TBLB and associated factors. METHODS: CT-guided TBLB was performed in 59 patients. Both conventional fluoroscopy and CT were used in all patients for TBLB. The biopsy forceps were advanced toward the lesion under conventional fluoroscopic guidance. CT was used to check whether the forceps were in the correct position. RESULTS: The average diameter of the lesions was 3.1 ± 1.0 cm. The biopsy forceps correctly reached the lesion in 43 patients by real-time CT. A diagnosis was made in 42 patients, and the overall diagnostic yield was 71.2%. The sensitivity for malignancy was 85.7%. In multivariate analysis, the only factor associated with diagnostic yield was forceps position assessed by CT scan (adjusted odds ratio 53.31; 95% confidence interval 5.31, 535.27; P = 0.001). CONCLUSION: CT-guided TBLB is a useful diagnostic tool for pulmonary nodules or masses. The correct positioning of biopsy forceps using CT is valuable for successful CT-guided TBLB.

Inhaled indacaterol for the treatment of COPD patients with destroyed lung by tuberculosis and moderate-to-severe airflow limitation: results from the randomized INFINITY study.

BACKGROUND AND OBJECTIVE: Pulmonary tuberculosis (TB) is a risk factor for chronic obstructive pulmonary disease (COPD); however, few clinical studies have investigated treatment effectiveness in COPD patients with destroyed lung by TB. The Indacaterol effectiveness in COPD patients with Tuberculosis history (INFINITY) study assessed the efficacy and safety of once-daily inhaled indacaterol 150 µg for the treatment of Korean COPD patients with destroyed lung by TB and moderate-to-severe airflow limitation. METHODS: This was a multicenter, double-blind, parallel-group study, in which eligible patients were randomized (1:1) to receive either once-daily indacaterol 150 µg or placebo for 8 weeks. The primary efficacy endpoint was change from baseline in trough forced expiratory volume in 1 s at Week 8; the secondary endpoints included changes in transition dyspnea index score and St George's Respiratory Questionnaire for COPD score at Week 8. Safety was evaluated over 8 weeks. RESULTS: Of the 136 patients randomized, 119 (87.5%) completed the study treatment. At Week 8, indacaterol significantly improved trough forced expiratory volume in 1 s versus placebo (treatment difference [TD] 140 mL, P<0.001). Statistically significant improvement in transition dyspnea index score (TD =0.78, P<0.05) and numerical improvement in St George's Respiratory Questionnaire for COPD score (TD =-2.36, P=0.3563) were observed with indacaterol versus placebo at Week 8. Incidence of adverse events was comparable between the treatment groups. CONCLUSION: Indacaterol provided significantly superior bronchodilation, significant improvement in breathlessness and improved health status with comparable safety versus placebo in Korean COPD patients with destroyed lung by TB and moderate-to-severe airflow limitation.

Suicidal ideation and suicide attempts in chronic obstructive pulmonary disease: the Korea National Health and Nutrition Examination Survey (KNHANES IV, V) from 2007-2012.

BACKGROUND: There is good evidence for an association between chronic obstructive pulmonary disease (COPD) and depression, but there are few studies on the relationship between COPD and suicidal ideation/suicidal attempts. AIMS: To evaluate the mental health of patients with COPD in Korea and to compare it with that of the general population. METHODS: We analysed data of 15,718 subjects (age ⩾40 years) who participated in the 2007-2012 Korea National Health and Nutrition Examination Survey. COPD was defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for people aged ⩾40 years. We compared the mental health outcomes of 2,506 patients with COPD (2,355 GOLD stages I and II; 151 GOLD stages III and IV) with those of 13,212 controls. RESULTS: Suicidal thoughts were reported by 16.0% of patients in stages I and II, by 23.8% of those in stages III and IV and by 15.7% of controls (P=0.023). Suicidal attempts were reported by 0.6% of patients in stages I and II, by 2.6% of those in stages III and IV and by 1.0% of controls (P=0.019). The crude odds ratio (OR) for suicidal ideation in those in stages III and IV was 1.68 (95% confidence interval (CI), 1.16-2.46), and the OR for suicidal attempts in stages III and IV was 2.83 (95% CI, 1.03-7.75). In multivariate analysis, the OR for suicidal ideation in stages III and IV was 1.67 (95% CI, 1.12-2.49) and that for suicidal attempts was 2.94 (95% CI, 1.03-8.31). CONCLUSIONS: GOLD stages III and IV COPD were associated with a marked increase in suicidal behaviour.