Sex-related disparities in cough-associated symptoms across different age groups.

BACKGROUND: Sex-related disparities in the prevalence of chronic cough have been consistently reported globally, with varying male-to-female ratios. OBJECTIVES: This study aimed to evaluate sex-related differences by comparing correlations between cough-related symptoms in males and females of different age groups. DESIGN: Adult patients with chronic cough who completed the Leicester Cough Questionnaire (LCQ) were recruited from 16 respiratory centers. METHODS: Correlation networks were constructed based on Spearman's correlation coefficients in males and females of various age groups. The distinct relationships of cough-related symptoms between subgroups were validated by an independent cohort. RESULTS: A total of 255 patients were enrolled in this study (male-to-female ratio, 1:1.71). The following LCQ items were highly correlated: embarrassment and interference with daily work, anxiety, and interference with overall life enjoyment/feeling of being fed up, interference with daily work and overall life enjoyment, interference with overall life enjoyment and feeling of being fed up, and feeling of being fed up and annoyance to partner/family/friends. The patterns of these correlations between LCQ items varied in males and females of different ages. The strongest interrelationship was observed in male patients aged >50 years old, which was similar to those in the validation cohort. CONCLUSION: The correlation patterns between cough-related symptoms vary significantly according to age and sex. Understanding the mechanisms underlying the development of cough-related symptoms may facilitate sex- and age-specific strategies for chronic cough.

Impact of National Public-Private Mix and Medical Expense Support Program to Control Tuberculosis in South Korea: An Interrupted Time Series Analysis.

Tuberculosis (TB) remains a major threat to global public health. Various measures at the national level have been implemented to control TB, and no evidence with long-term effectiveness has yet been evaluated on TB control programs. We confirmed the long-term effectiveness of the TB control programs in reducing overall burden in South Korea using interrupted time series analysis. Our finding suggests that, along with the public-private mix, relieving the economic burden of people with TB may complement achieving the End TB Strategy. For countries currently developing strategies for TB control, results may provide important insights in effective TB control.

Ambulatory oxygen therapy with documented self-monitoring of oxygen use improves health status among patients with chronic obstructive pulmonary disease.

Background: Home oxygen therapy is well known to improve survival among patients with severe chronic obstructive pulmonary disease (COPD). In Korea, home oxygen therapy has been reimbursed by national health care insurance since 2006. However, an adequate management strategy for home oxygen therapy is not yet established in Korea. This pilot study aimed to develop a new management strategy for home oxygen therapy. Methods: We developed a new home oxygen service strategy for COPD patients. The new strategy consists of patient education materials, "oxygen notes" for oxygen use self-monitoring, and provision of ambulatory oxygen. Using a structured questionnaire, we explored the usefulness of the new strategy and health status changes among patients before and after the study period. Results: Among 29 participants, the mean age was 69.6 years, and 62.1% were male. At the end of the study, the proportion of patients with severe dyspnea [modified Medical Research Council (mMRC) grade 4] decreased from 62.1% to 41.4%. The mean COPD assessment test score improved from 30.3 to 24.7, and 68.9% of patients scored above the minimum clinically important difference. The mean time and amount of ambulatory oxygen administration changed significantly by the end of the study. More than three-quarters of patients were satisfied with the educational material and oxygen note. Conclusions: We showed that the new home oxygen service strategy improved the health status of COPD patients. Larger-scale and longer-term research to validate these results is warranted.

Hospitalization increases while economic status deteriorates in late stages of chronic obstructive pulmonary disease: the Korean National Health and Nutrition Examination Survey for 2007-2015.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with frequent hospitalizations, higher mortality, and healthcare costs. Low-income COPD patients have higher rates of emergency department visits and hospitalization due to COPD exacerbation. However, other causes of admissions and their economic burden have not been well-elucidated. METHODS: We analyzed the Korean National Health and Nutrition Examination Survey (KNHANES) dataset for 2007-2015. The diagnosis and staging of COPD were based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. RESULTS: Among the 97,622 participants in KNHANES for 2007-2015, we selected 33,963 participants (4,430 with and 29,533 without COPD) aged ≥40 years, who underwent spirometry, and provided the admission history for the previous year. Participants with COPD had a higher admission rate than those without COPD (12.8% vs. 10.4%, P<0.001). The admission rate increased as the stage of COPD advanced from GOLD 1 to GOLD 4 for total causes (11.5%, 13.6%, 15.1%, and 25.0%, respectively, P<0.001) and respiratory illnesses (0.5%, 1.3%, 4.6%, and 12.5%, respectively, P<0.001). The proportion of the lowest quartile household income increased in the late stages of COPD (GOLD 1-4; 35.2%, 32.1%, 44.9%, and 70.8%, respectively, P<0.01). CONCLUSIONS: The hospitalization rate increased in advanced COPD, while GOLD stages 3 and 4 were associated with deterioration in economic status.

Differential features of chronic cough according to etiology and the simple decision tree for predicting causes.

Finding etiology of chronic cough is an essential part of treatment. Although guidelines include many laboratory tests for diagnosis, these are not possible in many primary care centers. We aimed to identify the characteristics and the differences associated with its cause to develop a clinical prediction model. Adult subjects with chronic cough who completed both Korean version of the Leicester Cough Questionnaire (K-LCQ) and COugh Assessment Test (COAT) were enrolled. Clinical characteristics of each etiology were compared using features included in questionnaires. Decision tree models were built to classify the causes. A total of 246 subjects were included for analysis. Subjects with asthma including cough variant asthma (CVA) suffered from more severe cough in physical and psychological domains. Subjects with eosinophilic bronchitis (EB) presented less severe cough in physical domain. Those with gastro-esophageal reflux disease (GERD) displayed less severe cough in all 3 domains. In logistic regression, voice hoarseness was an independent feature of upper airway cough syndrome (UACS), whereas female sex, tiredness, and hypersensitivity to irritants were predictors of asthma/CVA; less hoarseness was a significant feature of EB, and feeling fed-up and hoarseness were less common characteristics of GERD. The decision tree was built to classify the causes and the accuracy was relatively high for both K-LCQ and COAT, except for UACS. Voice hoarseness, degree of tiredness, hypersensitivity to irritants and feeling fed-up are important features in determining the etiologies. The decision tree may further assists classifying the causes of chronic cough.

Relationship Between Changes in Inhalation Treatment Level and Exacerbation of Chronic Obstructive Pulmonary Disease: Nationwide the Health Insurance and Assessment Service Database.

Background and Objective: Maintaining adequacy in chronic obstructive pulmonary disease (COPD) care is essential to sustain an adequate level of care. We aimed to assess the current status of COPD quality control and the influence of inhaler changes on disease-related health care utilization. Methods: The Health Insurance Review and Assessment Service (HIRA) nationwide database for reimbursed insurance claims from all medical institutions in South Korea from May 2014 to April 2017 was investigated. COPD care quality was assessed by the performance rate of spirometry, the percentage of persistent visit patients and patients prescribed a bronchodilator. The number of severe exacerbations was evaluated. Results: A total of 68,942 COPD patients were included for 3 years of longitudinal analyses. The overall spirometry enforcement rate was just over 50%, the percentage of regular follow-up patients was over 85%, and bronchodilators were prescribed to over 80% of the patients. COPD-related hospitalization or ER visit rates were 16.6%, 15.3%, and 17.8% for three consequent assessments, respectively. Inhaler changes were analyzed between the first and second assessments: 57.1% were maintained, 0.4% were changed to another class, 9% were escalated, and 5.2% were de-escalated. Only in the escalated group, especially those who changed from the mono to dual inhaler and dual to triple inhaler, had fewer hospitalizations or ER visits. Conclusion: Adequacy of COPD care status was not that high considering the low-enforcement rate of spirometry, but most patients were prescribed a bronchodilator and regularly followed up. Those who escalated inhaler treatment experienced less health care utilization.

Development and validation of the COugh Assessment Test (COAT).

BACKGROUND AND OBJECTIVE: A cough-specific quality-of-life questionnaire is recommended to assess the impact of cough; however, a simple instrument to quantify cough is required for everyday clinical practice. This study was aimed to develop a short patient-completed questionnaire (COugh Assessment Test, COAT). METHODS: The COAT was developed and validated by comparison with the Korean version of Leicester Cough Questionnaire (K-LCQ) and cough numeric rating scale (NRS, 0-10, 11-point scale) for chronic cough patients. RESULTS: Item selection identified five items regarding cough frequency, daily activity, sleep disturbance, fatigue and cough hypersensitivity (0-4 scaling of items, 0-20 score range) through reliability test cohort (n = 78). Test-retest reliability was strong (intra-class correlation coefficient = 0.88). The final COAT was compared with K-LCQ and cough NRS in a validation cohort (n = 323). In Rasch analysis, COAT fitted well to a unidimensional model. Pearson correlations of COAT versus K-LCQ (i) before treatment, (ii) after treatment; COAT versus cough NRS (iii) before treatment, (iv) after treatment; (v) delta-COAT versus delta-cough NRS, (vi) delta-COAT versus delta-K-LCQ were (i) -0.71, (ii) -0.81, (iii) 0.69, (iv) 0.82, (v) -0.66 and (vi) 0.72, respectively. CONCLUSION: The COAT is a useful, simple questionnaire for assessing and monitoring cough.

Awareness of chronic obstructive pulmonary disease in current smokers: a nationwide survey.

BACKGROUND/AIMS: Cigarette smoking is the most common risk factor for chronic obstructive pulmonary disease (COPD). However, few studies of the attitudes toward COPD of smokers, the group at risk of developing this condition, have been conducted. The purpose of this study was to explore the awareness of and attitudes toward COPD of current smokers. METHODS: The sample consisted of 502 individuals aged 45 and older from throughout Korea who smoked at least 10 packs of cigarettes per year. Telephone interviews using a structured questionnaire were conducted with respondents. RESULTS: First, we evaluated the health status of subjects, finding that 45.4% considered themselves to be in good health. We also asked about COPD-related symptoms, and 60.6% of subjects reported such symptoms. However, only 1.2% of subjects had been diagnosed with or treated for COPD, only 0.4% spontaneously mentioned COPD as a respiratory disease, and only 26.5% recognized COPD as a respiratory disease after seeing a list of such diseases. Television ranked as the top source of information about COPD. The willingness of 45.0% of subjects to stop smoking increased after being informed about COPD. CONCLUSIONS: Despite having COPD-related symptoms, most smokers did not know that COPD is a respiratory disease. The attitudes of smokers toward COPD and smoking cessation varied according to socioeconomic status. In summary, a continuous effort to increase the awareness of COPD among smokers is needed. Additionally, strategies tailored according to different socioeconomic groups will also be necessary.