No abstract

Objective: Chronic obstructive pulmonary disease (COPD) acute exacerbations are significant causes of morbidity and mortality. "Frequent exacerbator" phenotypes are considered a distinct subgroup and this phenotype has a negative effect on lung function, quality of life, activity, hospital admission, and mortality. We assess inhaler handling technique and adherence, and evaluate risk factors associated with frequent exacerbations in COPD patients. Methods: This study was a cross-sectional, case-control study. We prospectively enrolled 189 COPD patients from Yeungnam University Hospital from January 2018 to November 2018. Subjects were tested regarding their inhaler technique in face-to-face interviews with an advanced practice nurse of inhaler upon study entry. Frequency of moderate to severe COPD exacerbations were reviewed via electronic medical records during 12 months prior to study entry. Frequent exacerbations were defined as ≥2 moderate to severe exacerbations in the prior 12 months. Multivariate logistic regression was performed to identify risk factors for frequent exacerbations. Results: Among 189 COPD patients, 50 (26.5%) were frequent exacerbators. Based on univariate analyses, body mass index (BMI) < 25 kg/m 2 , lower forced expiratory volume in 1 s (FEV 1 ), higher mMRC, lower feeling of satisfaction with the inhaler, and any critical errors were potential risk factors for frequent exacerbations. Multivariate logistic regression analyses revealed that BMI < 25 kg/m 2 (OR, 2.855, 95% CI, 1.247-6.534; p=0.013), higher mMRC (OR, 1.625, 95% CI, 1.072-2.463; p=0.022), and any critical error (OR, 2.020, 95% CI, 1.021-3.999; p=0.044) were risk factors. Conclusion: Any critical error, BMI < 25 kg/m 2 and high mMRC are independent risk factors for frequent exacerbations in COPD patients. Careful monitoring and education around inhaler devices, particularly in frequent exacerbators, are important components of COPD treatment.

No abstract

Epidemiological data of Bordetella pertussis infection among adolescents and adults are limited in Korea. Patients (≥ 11 yr of age) with a bothersome cough for less than 30 days were enrolled during a 1-yr period at 22 hospitals in Korea. Nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and for bacteriologic culture. In total, 490 patients were finally enrolled, and 34 (6.9%) patients tested positive for B. pertussis; cough duration (14.0 days [7.0-21.0 days]) and age distribution were diverse. The incidence was the highest in secondary referral hospitals, compared to primary care clinics or tertiary referral hospitals (24/226 [10.6%] vs. 3/88 [3.4%] vs. 7/176 [4.0%], P = 0.012), and the peak incidence was observed in February and August (15.8% and 15.9%), with no confirmed cases between March and June. In the multivariate analysis, post-tussive vomiting was significantly associated with pertussis (odds ratio, 2.508; 95% confidence interval, 1.146-5.486) and secondary referral hospital showed a borderline significance. In conclusion, using a PCR-based method, 6.9% of adolescent and adult patients with an acute cough illness had pertussis infection in an outpatient setting. However, hospital levels and seasonal trends must be taken into account to develop a better strategy for controlling pertussis.Graphical Abstract

Purpose: Previous studies have used various definitions to classify chronic obstructive pulmonary disease (COPD) patients into chronic bronchitis (CB) and non-CB patients. This study was performed to identify differences among three definitions of CB based on the classical method, St. George's Respiratory Questionnaire (SGRQ), and the CAT (COPD Assessment Test) score. Patients and methods: We extracted data from the multicenter Korea COPD Subgroup Study (KOCOSS) cohort, for which patients recruited from among 47 medical centers in South Korea beginning in April 2012. Patients were classified according to three different definitions of CB: 1) classical definition; 2) SGRQ (using questions regarding cough and sputum); and 3) CAT score (comprising cough [CAT1] and sputum [CAT2] subscale scores). Results: A total of 2694 patients were enrolled in this study. The proportions of CB were 10.8%, 35.8%, and 24.0% according to the classical, SGRQ, and CAT definitions, respectively. The three definitions yielded consistently significant differences between CB and non-CB patients in modified Medical Research Council dyspnea scale CAT score, SGRQ score, number of moderate-to-severe exacerbations per year and forced expiratory volume in 1 second. By three definitions, CB consistently predicted future risk of exacerbation. The kappa coefficient of agreement between the classical definition and SGRQ definition was 0.29, that of the classical definition and CAT definition was 0.32, and that of the SGRQ definition and CAT definition was 0.44. Conclusion: Patients with CB according to the new definitions based on SGRQ or CAT score showed similar clinical characteristics to those defined according to the classical definition. The new CB definitions may be used as alternatives to the classical definition.