Background: Coronavirus disease 2019 (COVID-19) has spread worldwide rapidly. However, the effects of asthma, asthma medication and asthma severity on the clinical outcomes of COVID-19 have not yet been established. Methods: The study included 7590 de-identified patients, who were confirmed to have COVID-19 using the severe acute respiratory syndrome coronavirus 2 RNA-PCR tests conducted up to May 15, 2020; we used the linked-medical claims data provided by the Health Insurance Review and Assessment Service. Asthma and asthma severity (steps suggested by the Global Initiative for Asthma) were defined using the diagnostic code and history of asthma medication usage. Results: Among 7590 COVID-19 patients, 218 (2.9%) had underlying asthma. The total medical cost associated with COVID-19 patients with underlying asthma was significantly higher than that of other patients. Mortality rate for COVID-19 patients with underlying asthma (7.8%) was significantly higher than that of other patients (2.8%; p<0.001). However, asthma was not an independent risk factor for the clinical outcomes of COVID-19 after adjustment, nor did asthma medication use and asthma severity affect the clinical outcomes of COVID-19. However, use of oral short-acting β ₂ -agonists was an independent factor to increase the total medical cost burden. Patients with step 5 asthma showed significant prolonged duration of admission compared to those with step 1 asthma in both univariate and multivariate analysis. Conclusions: Asthma led to poor outcomes of COVID-19; however, underlying asthma, use of asthma medication and asthma severity were not independent factors for poor clinical outcomes of COVID-19, generally.

Purpose: Minimal (< 10 mm thick) pleural effusion (PE) may represent an early phase of malignant PE, but its clinical relevance has rarely been studied. Therefore, we examined the proportion of minimal PE in patients with non–small-cell lung cancer (NSCLC) and its impact on survival. We also considered possible accumulation mechanisms in our data set. Patients and Methods: On the basis of PE status from chest computed tomography scans at diagnosis, 2,061 patients were classified into three groups: no PE, minimal PE, and malignant PE. Twenty-one variables associated with four factors—patient, stage migration, tumor, and treatment—were investigated for correlation with survival. Results: Minimal PE presented in 272 patients (13.2%). Of 2,061 patients, the proportion of each stage was the following: 5.2% stage I, 10.9% stage II, 13.2% stage IIIA, 23.8% stage IIIB, and 13.9% stage IV. Minimal PE correlated significantly with shorter survival time than did no PE (median survival time, 7.7 v 17.7 months; log-rank P < .001), even after full adjustment with all variables (adjusted hazard ratio, 1.40; 95% CI, 1.21 to 1.62). Prognostic impact of minimal PE was higher in early versus advanced stages (P_interaction = .001). In 237 patients (87.8%) with minimal PE, pleural invasion or attachment as a direct mechanism was observed, and it was an independent factor predicting worse survival (P = .03). Conclusion: Minimal PE is a commonly encountered clinical concern in staging NSCLCs. Its presence is an important prognostic factor of worse survival, especially in early-stage disease.

Purpose: The forced mid-expiratory flow (FEF_25-75%) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF_25-75% can be an early predictor of chronic obstructive pulmonary disease (COPD). Patients and Methods: Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital. We selected 307 patients aged over 40 years without COPD who had normal PFT results at baseline and who had follow-up PFT records more than 1 year later. A FEF_25-75% z-score less than − 0.8435 was considered low. We defined COPD as a forced expiratory volume in one second/forced vital capacity value of less than 0.7 before July 31, 2019. Results: Among 307 patients, 91 (29.6%) had low FEF_25-75% at baseline. After 10 years, the incidence rate of COPD in the low FEF_25-75% group was significantly higher than that in the normal FEF_25-75% group (41.8% vs 7.4%; P-value< 0.001). The Cox proportional hazard model showed that age (hazard ratio [HR] 1.09; P-value< 0.001), smoking status (occasional smoker HR, 4.59; P-value< 0.001 and long-term smoker HR, 2.18; P-value=0.023), and low FEF_25-75% (HR, 3.31; P-value< 0.001) were predictive factors for the development of COPD. Conclusion: The FEF_25-75% value in patients with normal lung function is a useful predictor for the development of COPD. We should carefully monitor patients who present with low FEF_25-75% values, even if they have normal lung function.

The aim of this study was to confirm the synergistic effect of colistin/rifampicin combination therapy compared with colistin monotherapy in pneumonia caused by colistin-resistant Acinetobacter baumannii (CoRAB). The utility of the Etest was also assessed. Nine subjects with pneumonia caused by CoRAB were enrolled from 20 July 2016 to 21 June 2018. Subjects were randomised to colistin/rifampicin combination therapy or colistin monotherapy. After exclusion of one patient who dropped out, the microbiological response (MR) and clinical response (CR) on Day 14 and mortality on Day 30 were assessed. Etest was conducted using CoRAB isolated at study enrolment. The MR rate in the colistin/rifampicin combination group (100.0%) was better than that in the colistin group (40.0%), however the difference was not statistically significant (P=0.196). The CR rate was not significantly different between the two groups. The MR (100.0%) and CR (100.0%) rates in subjects with 'partial synergy' as shown by Etest were higher than those (25.0% and 50.0%, respectively) in subjects with 'indifferent' results (i.e. no synergistic effect), however the difference was not statistically significant (P=0.143 and 0.429, respectively). Mortality occurred in two subjects with 'indifferent' results by Etest. Colistin/rifampicin combination therapy may have potential to achieve MR in pneumonia caused by CoRAB; however, achieving CR with this treatment is doubtful. 'Partial synergy' of colistin and rifampicin, as shown by Etest, may be a good prognostic factor [ClinicalTrial.gov ID: NCT03622918].

Spirometry is a physiological test for assessing the functional aspect of the lungs using an objective indicator to measure the maximum amount of air that a patient can inhale and exhale. Acceptable spirometry testing needs to be conducted three times by an acceptable and reproducible method for determining forced vital capacity (FVC). Until the results of three tests meet the criteria of reproducibility, the test should be repeated up to eight times. Interpretation of spirometry should be clear, concise, and informative. Additionally, spirometry should guarantee optimal quality prior to the interpreting spirometry results. Our guideline adopts a fixed normal predictive value instead of the lower limit of normal as the reference value because fixed value is more convenient and also accepts FVC instead of vital capacity (VC) because measurement of VC using a spirometer is impossible. The bronchodilator test is a method for measuring the changes in lung capacity after inhaling a short-acting β-agonist that dilates the airway. When an obstructive ventilatory defect is observed, this test helps to diagnose and evaluate asthma and chronic obstructive pulmonary disease by measuring reversibility with the use of an inhaled bronchodilator. A positive response to a bronchodilator is generally defined as an increase of ≥12% and ≥200 mL as an absolute value compared with a baseline in either forced expiratory volume at 1 second or FVC.