Components of the Chronic Obstructive Pulmonary Disease Assessment Test Associated with the Exacerbation of Severe Chronic Obstructive Pulmonary Disease Patients.

INTRODUCTION: The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) score is widely used for evaluating the health status of patients diagnosed with COPD. The aim of this study was to identify which components of the CAT are associated with exacerbations in severe COPD patients. METHODS: Using data from the Korean COPD Subgroup Study (KOCOSS), we identified 3,440 COPD patients, among which 1,027 patients are classified as having severe COPD based on spirometry results. The CAT scores on 8 items were evaluated and classified into respiratory and non-respiratory categories. We analyzed the association between CAT item scores and moderate-to-severe exacerbations during study enrollment and the following years. RESULTS: Patients with a history of moderate-to-severe exacerbations had higher scores on non-respiratory CAT components. Longitudinal CAT scores on all items after enrollment were higher in the moderate-to-severe exacerbation group. Additionally, the frequency of severe exacerbations was associated with specific CAT components related to limited activities, confidence leaving home, sleeplessness, and energy. CONCLUSIONS: This study revealed that the non-respiratory CAT component scores were statistically significant factors for predicting the moderate-to-severe exacerbation of severe COPD patients. Non-respiratory symptoms and functional limitations should be considered in patients with severe COPD. Interventions, such as pulmonary rehabilitation, may be needed to improve patients' overall well-being and prevent exacerbations.

The health-related quality-of-life of chronic obstructive pulmonary disease patients and disease-related indirect burdens.

BACKGROUND/AIMS: Many chronic obstructive pulmonary disease (COPD) patients have physical limitations. We investigated EuroQol five-dimensions five-level (EQ-5D-5L) of COPD patients to assess quality of life, and assessed indirect burden including time expenditure to visit doctor, home care rate, and caregiver related burden. METHODS: We recruited 355 COPD patients according to severity of airflow limitation that severity was set at 10% mild, 40% moderate, 30% severe, and 20% very severe in two primary and 11 secondary/tertiary hospitals. Eligible patients were aged ≥ 40 years, who have been diagnosed with COPD for more than 1 year. Patients were recruited between June 2015 and October 2016. RESULTS: The quality of life tended to decline with age, from mild to very severe impairment, as revealed by the EQ-5D-5L scores and the EQ visual analog scale. Family caregivers accompanied 22.6% of patients who visited outpatient clinics, and 25% of stage IV COPD patients. During emergency visits and hospitalization, this figure increased to > 60%. The home care rates were 28.5% for stage I patients, and 34.4, 31.8, and 52% for stage II to IV patients, respectively. The percentage of caregivers who stopped working was 13.6%. The EQ-5D index was strongly associated with the dyspnea scale (r = -0.64, p < 0.001). The average required time to see a doctor and visit the pharmacy was 154 minutes. CONCLUSION: In patients with COPD, the EQ-5D index decreased and disease-related home caregiving increased with airflow limitation. We considered the caregiver- related burden when making a strategy for COPD management.

Direct and Indirect Costs of Chronic Obstructive Pulmonary Disease in Korea.

BACKGROUND: Understanding the burden of disease is important to establish cost-effective treatment strategies and to allocate healthcare resources appropriately. However, little reliable information is available regarding the overall economic burden imposed by chronic obstructive pulmonary disease (COPD) in Korea. METHODS: This study is a multicenter observational research on the COPD burden in Korea. Total COPD costs were comprised of three categories: direct medical, direct non-medical, and indirect costs. For direct medical costs, institutional investigation was performed at 13 medical facilities mainly based on the claims data. For direct non-medical and indirect costs, site-based surveys were administered to the COPD patients during routine visits. Total costs were estimated using the COPD population defined in the recent report. RESULTS: The estimated total costs were approximately 1,245 million US dollar (1,408 billion Korean won). Direct medical costs comprised approximately 20% of the total estimated costs. Of these, formal medical costs held more than 80%. As direct non-medical costs, nursing costs made up the largest percentage (39%) of the total estimated costs. Costs for COPD-related loss of productivity formed four fifths of indirect costs, and accounted for up to 33% of the total costs. CONCLUSION: This study shows for the first time the direct and indirect costs of COPD in Korea. The total costs were enormous, and the costs of nursing and lost productivity comprised approximately 70% of total costs. The results provide insight for an effective allocation of healthcare resources and to inform establishment of strategies to reduce national burden of COPD.

Heterogeneity of asthma and COPD overlap.

BACKGROUND: Asthma and COPD are heterogeneous diseases. Patients with both disease features (asthma-COPD overlap [ACO]) are common. However, clinical characteristics and socio-economic burden of ACO are still controversial. The aim of this study was to identify the heterogeneity of ACO and to find out the subtypes with clinical impact among ACO subtypes. METHODS: In the Korean National Health and Nutrition Examination Survey (KNHANES) conducted between 2007 and 2012, subjects who were ≥40 years and had prebronchodilator FEV1/FVC <0.7 and FEV1 ≥50% predicted were included. The presence or absence of self-reported wheezing was indicated by W+ or W- and used as an index of airway hyper-responsiveness. S+/S- was defined as subjects who were smokers/never smokers. The subjects were divided into the following four groups: W-S-, W-S+, W+S-, and W+S+. W+S- and W+S+ were asthma-predominant ACO and COPD-predominant ACO, respectively. KNHANES and linked National Health Insurance data were analyzed. RESULTS: The asthma-predominant ACO group showed the lowest socioeconomic status, FEV1, FVC% predicted, and quality of life (QoL) levels. The COPD-predominant ACO group showed the highest hospitalization rate, outpatient medical cost, and total and outpatient health care utilization. COPD-predominant ACO was associated with exacerbations compared to the W-S- group (adjusted odds ratio [aOR], 1.79; 95% confidence interval [CI], 1.12-2.85; P=0.015) and W-S+ group (OR 2.11; 95% CI 1.43-3.10; P<0.001). COPD-predominant ACO was associated with increased medical cost. CONCLUSION: Asthma-predominant ACO individuals displayed poorer socioeconomic status and QoL compared to the COPD-predominant ACO group. The COPD-predominant ACO group displayed more frequent exacerbations and greater medical costs. Considering the heterogeneity of ACO, it is desirable to identify subtypes of ACO patients and appropriately allocate limited medical resources.

Different impacts of respiratory symptoms and comorbidities on COPD-specific health-related quality of life by COPD severity.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often have poor health-related quality of life (HRQoL) that is disproportionate to their degree of airflow limitation. This study evaluated the association between St George's Respiratory Questionnaire for COPD (SGRQ-C) score and forced expiratory volume in one second and investigated the factors responsible for high SGRQ-C score according to severity of airflow limitation. METHODS: Data from 1,264 COPD patients were obtained from the Korean COPD Subgroup Study (KOCOSS) cohort. Patients were categorized into two groups according to severity of airflow limitation: mild-to-moderate and severe-to-very severe COPD groups. We evaluated the clinical factors associated with high SGRQ-C score (≥25) in each COPD patient group. RESULTS: Of the 1,264 COPD patients, 902 (71.4%) had mild-to-moderate airflow limitation and 362 (28.6%) had severe-to-very severe airflow limitation. Of the mild-to-moderate COPD patients, 59.2% (534/902) had high SGRQ-C score, while 80.4% (291/362) of the severe-to-very severe COPD patients had high SGRQ-C score. The association between SGRQ-C score and post-bronchodilator forced expiratory volume in one second (% predicted) was very weak in the mild-to-moderate COPD patients (r=-0.103, p=0.002) and weak in the severe-to-very severe COPD patients (r=-0.219, p<0.001). Multiple logistic regression analysis revealed that age, being an ex- or current smoker, lower level of education, cough, dyspnea, and number of comorbidities with congestive heart failure, hyperlipidemia, and depression were significantly associated with high SGRQ-C score in mild-to-moderate COPD patients. In comparison, being an ex-smoker and having respiratory symptoms including sputum and dyspnea were significant factors associated with high SGRQ-C score in severe-to-very severe COPD patients. CONCLUSIONS: In addition to the respiratory symptoms of dyspnea and cough, high SGRQ-C score was associated with extra-pulmonary comorbidities in mild-to-moderate COPD patients. However, only respiratory symptoms such as sputum and dyspnea were significantly associated with high SGRQ-C score in severe-to-very severe COPD patients. This indicates the need for an improved management strategy for relieving respiratory symptoms in COPD patients with poor HRQoL. In addition, attention should be paid to extra-pulmonary comorbidities, especially in mild-to-moderate COPD patients with poor HRQoL.

Identification of subtypes in subjects with mild-to-moderate airflow limitation and its clinical and socioeconomic implications.

PURPOSE: The purpose of this study was to identify subtypes in patients with mild-to-moderate airflow limitation and to appreciate their clinical and socioeconomic implications. METHODS: Subjects who were aged ≥20 years and had forced expiratory volume in 1 second (FEV1) ≥60% predicted and FEV1/forced vital capacity <0.7 were selected from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) in 2007-2012. The data were merged to the National Health Insurance reimbursement database during the same period. k-Means clustering was performed to explore subtypes. For clustering analysis, six key input variables - age, body mass index (BMI), FEV1% predicted, the presence or absence of self-reported wheezing, smoking status, and pack-years of smoking - were selected. RESULTS: Among a total of 2,140 subjects, five groups were identified through k-means clustering, namely putative "near-normal (n=232)," "asthmatic (n=392)," "chronic obstructive pulmonary disease (COPD) (n=37)," "asthmatic-overlap (n=893)," and "COPD-overlap (n=586)" subtypes. Near-normal group showed the oldest mean age (72±7 years) and highest FEV1 (102%±8% predicted), and asthmatic group was the youngest (46±9 years). COPD and COPD-overlap groups were male predominant and all current or ex-smokers. While asthmatic group had the lowest prescription rate despite the highest proportion of self-reported wheezing, COPD, asthmatic-overlap, and COPD-overlap groups showed high prescription rate of respiratory medicine. Although COPD group formed only 1.7% of total subjects, they showed the highest mean medical cost and health care utilization, comprising 5.3% of the total medical cost. When calculating a ratio of total medical expense to household income, the mean ratio was highest in the COPD group. CONCLUSION: Clinical and epidemiological heterogeneities of subjects with mild-to-moderate airflow limitation and a different level of health care utilization by each subtype are shown. Identification of a subtype with high health care demand could be a priority for effective utilization of limited resources.

Discrepancies between modified Medical Research Council dyspnea score and COPD assessment test score in patients with COPD.

BACKGROUND AND OBJECTIVE: According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, either a modified Medical Research Council (mMRC) dyspnea score of ≥2 or a chronic obstructive pulmonary disease (COPD) assessment test (CAT) score of ≥10 is considered to represent COPD patients who are more symptomatic. We aimed to identify the ideal CAT score that exhibits minimal discrepancy with the mMRC score. METHODS: A receiver operating characteristic curve of the CAT score was generated for an mMRC scores of 1 and 2. A concordance analysis was applied to quantify the association between the frequencies of patients categorized into GOLD groups A-D using symptom cutoff points. A κ-coefficient was calculated. RESULTS: For an mMRC score of 2, a CAT score of 15 showed the maximum value of Youden's index with a sensitivity and specificity of 0.70 and 0.66, respectively (area under the receiver operating characteristic curve [AUC] 0.74; 95% confidence interval [CI], 0.70-0.77). For an mMRC score of 1, a CAT score of 10 showed the maximum value of Youden's index with a sensitivity and specificity of 0.77 and 0.65, respectively (AUC 0.77; 95% CI, 0.72-0.83). The κ value for concordance was highest between an mMRC score of 1 and a CAT score of 10 (0.66), followed by an mMRC score of 2 and a CAT score of 15 (0.56), an mMRC score of 2 and a CAT score of 10 (0.47), and an mMRC score of 1 and a CAT score of 15 (0.43). CONCLUSION: A CAT score of 10 was most concordant with an mMRC score of 1 when classifying patients with COPD into GOLD groups A-D. However, a discrepancy remains between the CAT and mMRC scoring systems.

CT-based assessment of renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones.

PURPOSE: The purpose of our study was to evaluate computed tomography (CT) imaging factors related to renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones. MATERIALS AND METHODS: The study included 94 patients who had acute unilateral ureteral obstruction due to a urinary stone and a normal contralateral kidney. We retrospectively investigated the serum creatinine (SCr) levels immediately prior to CT examination and at least 1 week after treatment. CT examinations were performed using a CT urography protocol, including pre- and post-contrast images. The 67 patients with a SCr change of less than 0.3 mg/dL constituted group A. The other 27 patients with a SCr decrease of more than 0.3 mg/dL constituted group B. To evaluate factors related to renal function impairment, differences in CT imaging factors between the two groups, including the cortical and medullary density, renal and pelvic anteroposterior diameter, and perinephric fluid, were statistically analyzed. RESULTS: The SCr immediately prior to CT examination significantly differed between the two groups. The follow-up SCr after resolution did not significantly differ between the two groups. The difference in the mean cortical and medullary HU on the nephrographic phase between the obstructed kidney and normal kidney was higher in group B than in group A (27.1 ± 23.1 and 69.4 ± 59.1 vs. 5.7 ± 8.8 and 31.8 ± 34.8; p < 0.001 and p = 0.004, respectively). The cut-off point for the difference in the mean cortical HU on the nephrographic phase between the obstructed kidney and normal kidney for renal function impairment was 15 HU, as determined by a receiver operating characteristic curve analysis. CONCLUSIONS: Patients with significantly impaired renal function due to an acute unilateral ureteral obstruction may show a decreased nephrogram of the affected kidney and a significant difference in the HU on the nephrographic phase between the obstructed and normal kidney.

The association between inhaled long-acting bronchodilators and less in-hospital care in newly-diagnosed COPD patients.

BACKGROUND: Although the efficacy of inhaled long-acting bronchodilators has been well documented in randomised controlled studies, whether similar effects are obtained in real-life clinical practice is not clear. In this study, we analysed the effect of inhaled long-acting bronchodilators in newly-diagnosed COPD patients. METHODS: The Korean Health Insurance Review and Assessment Service databases were used. Participants ≥40-years-old who had not been diagnosed with COPD between 2007 and 2008 but were diagnosed and prescribed COPD medication in 2009 were designated as newly-diagnosed COPD patients. Patients were divided into three groups based on the use of bronchodilators, an inhaled long-acting bronchodilator (LA-B), an inhaled short-acting bronchodilator (SA-B) and an oral medication (OM) group. RESULTS: A total of 77,480 newly-diagnosed COPD patients with a mean age of 68.5 years, among which 43,530 (56.2%) were men, were included in the study. ER visits and hospitalisation were associated with SA-B group, male gender, older age, Medicaid coverage, tertiary healthcare centre visits and higher comorbidities. Multivariate analysis showed that the SA-B group was associated with more ER visits, recurrent ER visits, hospitalisation and recurrent hospitalisation (adjusted ORs [95% confidence intervals] = 4.32 [3.93-4.75], 6.19 [5.24-7.30], 5.04 [2.95-3.39], and 8.49 [7.67-9.39], respectively) compared with the LA-B group. Medical utilisation cost was also higher in the SA-B group. CONCLUSION: Inhaled long-acting bronchodilator use was associated with lower rates of hospitalisation, fewer ER visits and lower medical costs in newly-diagnosed COPD patients in real-life clinical practice.

Medical utilization and cost in patients with overlap syndrome of chronic obstructive pulmonary disease and asthma.

BACKGROUND: Little information is available regarding medical utilization and cost in patients with overlap syndrome of chronic obstructive pulmonary disease (COPD) and asthma. The purpose of this study is to analyze medical utilization and cost in patients with overlap syndrome and to compare them to COPD patients without asthma. METHODS: Using the 2009 Korean National Health Insurance (NHI) database, COPD patients were identified. Medical utilization and costs were also analyzed. RESULTS: Of a total of 185,147 patients identified with COPD, 101,004 patients were classified with overlap syndrome of COPD and asthma and 84,143 patients with COPD without asthma. In 2009, the percentages of emergency room visits, admissions, and intensive care unit admissions were 14.6%, 30.5%, and 0.5%, respectively, in the patients with overlap syndrome group and 5.0%, 14.1%, and 0.2%, respectively, in the COPD patients without asthma group (p < 0.05 for all comparisons). The cost of medical utilization was 790 ± 71 US dollars per person and 3,373 ± 4,628 dollars per person for outpatient and inpatient services, respectively, in the patients with overlap syndrome and 413 ± 512 and 3,010 ± 5,013, respectively, in the COPD patients without asthma (p < 0.05 for all comparisons). Multiple linear regression showed that age, sex, overlap syndrome, hospitalization in the last year, low socioeconomic status, and type of hospital use were significant factors affecting medical utilization and cost. CONCLUSIONS: In patients with overlap syndrome, both medical utilization and cost were higher than in COPD patients without asthma.

The health care burden of high grade chronic obstructive pulmonary disease in Korea: analysis of the Korean Health Insurance Review and Assessment Service data.

BACKGROUND: Patients with high grade chronic pulmonary obstructive disease (COPD) account for much of the COPD-related mortality and incur excessive financial burdens and medical care utilization. We aimed to determine the characteristics and medical care use of such patients using nationwide data from the Korean Health Insurance Review and Assessment Service in 2009. MATERIALS AND METHODS: Patients with COPD were identified by searching with the International Classification of Diseases-10th Revision for those using medication. Patients with high grade COPD were selected based on their patterns of tertiary institute visits and medication use. RESULTS: The numbers of patients with high grade COPD increased rapidly in Korea during the study period, and they showed a high prevalence of comorbid disease. The total medical costs were over three times higher in patients with high grade COPD compared with those without it ($3,744 versus $1,183; P < 0.001). Medication costs comprised the largest portion of medical cost, but most impact came from hospitalization and exacerbation in both groups of patients. COPD grade and hospitalization in the previous year were the major factors affecting medical costs and days of utilizing health care resources. CONCLUSION: Patients with high grade COPD impose a high economic burden on the health care system in Korea. Prevention of progression to high grade COPD is important, both clinically and economically.

Mortality after in-hospital cardiopulmonary resuscitation: multicenter analysis in Korea.

PURPOSE: The purpose of this study is to evaluate factors associated with the mortality of patients admitted to intensive care units (ICUs) after in-hospital cardiopulmonary resuscitation (CPR) and the impact of a hospital rapid response system (RRS) on patient mortality in Korea. MATERIALS AND METHODS: A prospective multicenter cohort study was done in 22 ICUs of 15 centers from July 1, 2010, to January 31, 2011. We only enrolled patients admitted to ICUs after in-hospital CPR and divided eligible patients into 2 groups-survivors and nonsurvivors. RESULTS: Among 4617 patients, 150 patients were admitted post-CPR, 76 died, and 74 survived. At 24 hours, the Sequential Organ Failure Assessment score, Simplified Acute Physiology Score II, and the best Glasgow Coma Scale were significantly lower in the nonsurvivors than in the survivors. In multivariate analysis, the Simplified Acute Physiology Score II and presence of lower respiratory infection were both independently associated with mortality. At the first hour after admission, lowest serum potassium and highest heart rate were associated with mortality. At 24 hours after admission, lowest mean arterial pressure, HCO3 level, and venous oxygen saturation level; highest heart rate; and use of vasoactive drugs were associated with mortality. The mortality of patients in hospitals with an RRS was not significantly different from that of hospitals without an RRS. CONCLUSION: Various physiologic and laboratory parameters were associated with the mortality of post-CPR ICU admitted patients, and the presence of an RRS did not reduce mortality of these patients in our study.

Quantitative assessment of emphysema, air trapping, and airway thickening on computed tomography.

The severity of chronic obstructive pulmonary disease (COPD) is evaluated not only by airflow limitation but also by factors such as exercise capacity and body mass index. Recent advances in CT technology suggest that it might be a useful tool for evaluating the severity of the disease components of COPD. The aim of this study is to evaluate the correlation between the parameters measured on volumetric CT, including the extent of emphysema, air trapping, and airway thickening, and clinical parameters. CT scans were performed in 34 patients with COPD at full inspiration and expiration. We used in-house software to measure CT parameters, including volume fraction of emphysema (V(950)), mean lung density (MLD), CT air trapping index (CT ATI), segmental bronchial wall area (WA), lumen area (LA), and wall area percent (WA%). We found that the CT parameters were correlated with the pulmonary function test (PFT) results, body mass index (BMI), the modified Medical Research Council Dyspnea scale (MMRC scale), the six-minute-walk distance (6MWD), and the BODE index. V(950 insp) correlated to the BMI, FEV(1), 6MWD, and the BODE index. The CT ATI correlated with the physiologic ATI (VC-FVC) (R=0.345, p=0.045) and the MMRC scale (R=0.532, p=0.001). There was a positive correlation between the WA% and the BMI (R=0.563, p<0.001). MLD(exp) showed the strongest correlation with the BODE index (R= -0.756, p<0.001). We conclude that the severity of emphysema and air trapping measured on CT correlated with the PFT parameters 6MWD and BMI.