Predictors, mortality, and health outcomes of intensive phase non-adherence to a regimen in patients with drug-susceptible tuberculosis: a nationwide linkage database

OBJECTIVES

The clinical importance of adhering to the regimen in tuberculosis patients has been widely investigated, but most studies were conducted in controlled settings and in limited populations. We aimed to measure the level of real-world adherence during intensive phase and investigate the predictors and the risk of mortality and health outcomes of intensive phase non-adherence in tuberculosis patients.

STUDY DESIGN

We conducted a nationwide cohort study by linking the Korean National Tuberculosis Surveillance System and the National Health Information Database.

METHODS

We included all incident drug-susceptible tuberculosis patients who initiated the regimens recommended by the World Health Organization from 2013 to 2018. Adherence was measured using the proportion of days covered (poor [<50%], moderate [50%-79%], and high [≥80%]). We used logistic regression model to assess predictors and the Cox proportional hazard model to evaluate the risk of mortality and health outcomes with intensive phase non-adherence.

RESULTS

Of 46,818 patients, there were 8% and 11% with poor and moderate adherent groups, respectively. Age ≥45 years, insulin use, and history of renal failure were predictors of non-adherence. Compared with high adherent group, poor and moderate adherent groups were associated with a substantial risk of mortality (poor: hazard ratio, 2.14 [95% confidence interval, 1.95-2.34]; moderate: 1.76 [1.62-1.92]). Similar trends were observed for health outcomes. Stratified analyses showed a higher risk of mortality in patients with medical aid, low income, and history of renal failure, systematic corticosteroids, and immunomodulators.

CONCLUSIONS

Non-adherence during intensive phase increased mortality risk by twofold, underscoring targeted intervention for high-risk population, including advanced diabetes, and immunocompromised patients.

Development of the Rapid Cough Questionnaire: Key item identification

BACKGROUND

The Leicester Cough Questionnaire (LCQ) is a reliable tool for measuring the multidimensional impact of cough on patients' quality of life; however, its scoring algorithm is lengthy and complex for routine clinical use.

OBJECTIVE

The study aimed to develop a simplified version of the LCQ, the Rapid Cough Questionnaire (RCQ), as a substitue in clinical practice and validate the RCQ using an independent cohort.

METHODS

To select items for the RCQ score, a correlation network was used to determine the items from each domain that were strongly correlated with the total LCQ score. The final items for the RCQ were selected on the basis of the centrality of the node degree, betweenness, and closeness in the correlation network.

RESULTS

The RCQ score was derived from 3 items: tiredness (LCQ3) in the physical domain, the feeling of being fed up (LCQ13) in the psychological domain, and annoyance with partner/family/friends (LCQ19) in the social domain. The correlation between the LCQ and RCQ was high, with a coefficient of 0.93 (P < .001). The mean score of the RCQ was 11.2 ± 3.2, with scores ranging from 5.15 to 19.55. The minimal clinically important difference in the RCQ score was calculated to be 1.6 using a distribution-based method. The concurrent validity of the LCQ and the RCQ with cough numeric rating scale was similar. In the validation cohort, the correlation between the LCQ and RCQ scores was consistent regardless of sex and etiology.

CONCLUSION

The RCQ score, which is concise, reliable, and valid, can be a valuable tool for patient assessment, particularly in clinical practice.

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

Tuberculosis (TB) remains a major threat to global public health, various measures at 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. Along with the Public-Private Mix, our finding suggests that relieving the economic burden of people with TB may further complement in achieving the End TB strategy. For countries currently developing strategies for TB control, results may provide important insights in effective TB control.

Real-world outcome of crizotinib for anaplastic lymphoma kinase-positive lung cancer: Multicenter retrospective analysis in South Korea

BACKGROUND

About 3%-5% of non-small cell lung cancer (NSCLC) presents positive anaplastic lymphoma kinase (ALK). Recently, several target agents have been approved as a treatment for ALK-positive NSCLC. This study aimed to analyze the real-world efficacy and outcome when administered crizotinib, the first approved target agent for ALK-positive NSCLC, according to first- or late-line treatment.

METHODS

A total of 290 patients with ALK-positive advanced NSCLC who were treated with crizotinib in 15 institutions in South Korea from January 2009 to December 2018 were enrolled.

RESULTS

The median age of patients was 57.0 years, and 50.3% were male. The median follow-up duration was 29.3 months. Among them, 113 patients received crizotinib as first-line therapy. The objective response rate (ORR) was 60.1% (57.0% for first-line recipients, 61.8% for second-/later-line). Median (95% CI) progression-free survival (PFS) was 13.7 (11.6-17.0) months. For first-line recipients, overall survival (OS) was 26.3 (17.6-35.0) months. No significant difference in ORR, PFS and OS, according to the setting of crizotinib initiation, was observed. In a multivariate Cox regression analysis, old age, male gender, initially metastatic, and number of metastatic organs were associated with poor PFS and OS. The most common adverse events were nausea and vomiting, and severe adverse event leading to dose adjustment was hepatotoxicity.

CONCLUSIONS

ORR, PFS, OS, and adverse event profiles were comparable to previous clinical trials. Our findings could aid in the efficient management of ALK-positive lung cancer patients.

Strategies to Improve Smoking Cessation for Participants in Lung Cancer Screening Program: Analysis of Factors Associated with Smoking Cessation in Korean Lung Cancer Screening Project (K-LUCAS)

PURPOSE

Smoking cessation intervention is one of the key components of successful lung cancer screening program. We investigated the effectiveness and related factors of smoking cessation services provided to the participants in a population-based lung cancer screening trial.

MATERIALS AND METHODS

The Korean Lung Cancer Screening Project (K-LUCAS) is a nationwide, multi-center lung cancer screening trial that evaluates the feasibility of implementing population-based lung cancer screening. All 5,144 current smokers who participated in the K-LUCAS received a mandatory smoking cessation counseling. Changes in smoking status were followed up using a telephone survey in 6 months after lung cancer screening participation. The lung cancer screening's impact on smoking cessation is analyzed by variations in the smoking cessation interventions provided in screening units.

RESULTS

Among 4,136 survey responders, participant's motivation to quit smoking increased by 9.4% on average after lung cancer screening. After 6 months from the initial screening, 24.3% of participants stopped smoking, and 10.6% of participants had not smoked continuously for at least 6 months after screening. Over 80% of quitters stated that participation in lung cancer screening motivated them to quit smoking. Low-cost public smoking cessation program combined with lung cancer screening increased the abstinence rates. The smokers were three times more likely to quit smoking when the smoking cessation counseling was provided simultaneously with low-dose computed tomography screening results than when provided separately.

CONCLUSION

A mandatory smoking cessation intervention integrated with screening result counselling by a physician after participation in lung cancer screening could be effective for increasing smoking cessation attempts.

Lung Cancer Screening in Asia: An Expert Consensus Report

INTRODUCTION

The incidence and mortality of lung cancer are highest in Asia compared with Europe and USA, with the incidence and mortality rates being 34.4 and 28.1 per 100,000 respectively in East Asia. Diagnosing lung cancer at early stages makes the disease amenable to curative treatment and reduces mortality. In some areas in Asia, limited availability of robust diagnostic tools and treatment modalities, along with variations in specific health care investment and policies, make it necessary to have a more specific approach for screening, early detection, diagnosis, and treatment of patients with lung cancer in Asia compared with the West.

METHOD

A group of 19 advisors across different specialties from 11 Asian countries, met on a virtual Steering Committee meeting, to discuss and recommend the most affordable and accessible lung cancer screening modalities and their implementation, for the Asian population.

RESULTS

Significant risk factors identified for lung cancer in smokers in Asia include age 50 to 75 years and smoking history of more than or equal to 20 pack-years. Family history is the most common risk factor for nonsmokers. Low-dose computed tomography screening is recommended once a year for patients with screening-detected abnormality and persistent exposure to risk factors. However, for high-risk heavy smokers and nonsmokers with risk factors, reassessment scans are recommended at an initial interval of 6 to 12 months with subsequent lengthening of reassessment intervals, and it should be stopped in patients more than 80 years of age or are unable or unwilling to undergo curative treatment.

CONCLUSIONS

Asian countries face several challenges in implementing low-dose computed tomography screening, such as economic limitations, lack of efforts for early detection, and lack of specific government programs. Various strategies are suggested to overcome these challenges in Asia.

Final Report on Real-World Effectiveness of Sequential Afatinib and Osimertinib in EGFR-Positive Advanced Non-Small Cell Lung Cancer: Updated Analysis of the RESET Study

PURPOSE

This study aimed to report the final analysis of time-on-treatment (TOT) and overall survival (OS) in patients with advanced-stage epidermal growth factor receptor (EGFR)+ non-small cell lung cancer (NSCLC) who received sequential afatinib and osimertinib and to compare the outcomes with other second-line regimens (comparator group).

MATERIALS AND METHODS

In this updated report, the existing medical records were reviewed and rechecked. TOT and OS were updated and analyzed according to clinical features using the Kaplan-Meier method and log-rank test. TOT and OS were compared with those of the comparator group, in which most patients received pemetrexed-based treatments. A multivariable Cox proportional hazard model was used to evaluate features that could affect survival outcomes.

RESULTS

The median observation time was 31.0 months. The follow-up period was extended to 20 months. A total of 401 patients who received first-line afatinib were analyzed (166 with T790M+ and second-line osimertinib, and 235 with unproven T790M and other second-line agents). Median TOTs on afatinib and osimertinib were 15.0 months (95% confidence interval [CI], 14.0 to 16.1) and 11.9 months (95% CI, 8.9 to 14.6), respectively. The median OS in the osimertinib group was 54.3 months (95% CI, 46.7 to 61.9), much longer than that in the comparator group. In patients who received osimertinib, the OS was longest with Del19+ (median, 59.1; 95% CI, 48.7 to 69.5).

CONCLUSION

This is one of the largest real-world studies reporting the encouraging activity of sequential afatinib and osimertinib in Asian patients with EGFR+ NSCLC who acquired the T790M mutation, particularly Del19+.

Real-World Safety and Effectiveness of Fluticasone Furoate/Vilanterol in Patients with Asthma and/or Chronic Obstructive Pulmonary Disease: A Post-Marketing Study in Korea

BACKGROUND AND OBJECTIVE

Fluticasone furoate/vilanterol (FF/VI; RELVAR ELLIPTA) is approved in Korea for patients with asthma or chronic obstructive pulmonary disease (COPD). This study evaluated the effectiveness and safety of FF/VI in Korean patients with asthma and/or COPD over a 6-year period.

METHODS

This was an open-label, multicentre, observational, post-marketing surveillance study in patients newly treated with FF/VI (100 or 200 μg/25 μg once daily). Safety endpoints were the incidence of adverse events (AEs), including unexpected AEs/adverse drug reactions (ADRs) and serious AEs/ADRs. Effectiveness was assessed after 24 weeks by Global Physician Assessment (logistic regression) and forced expiratory volume in 1 s (FEV1; paired t-tests).

RESULTS

Of the 3426 patients enrolled across 45 hospitals between July 2014 and June 2020, 3216 were included in the safety analysis (50.5% female; mean age ± standard deviation [SD]: 58.6 ± 16.3 years). Overall incidence of AEs was 30.9% (n = 992); 4.1% (n = 132) were ADRs. Serious AEs were reported in 4.1% (n = 132) of patients; 0.1% (n = 4) were ADRs. Of 1543 patients analysed for symptomatic improvement, 89.2% (n = 1377) improved, 9.4% (n = 145) were unchanged, and 1.4% (n = 21) worsened. Mean FEV1 (difference ± SD) increased significantly in patients with asthma (0.09 ± 0.29 L; p < 0.0001), COPD (0.11 ± 0.24 L; p = 0.0011), or both (0.05 ± 0.18 L; p = 0.0399), indicating improved lung function.

CONCLUSION

In this real-world study, FF/VI administered to Korean patients was well tolerated and effective for the treatment of asthma and COPD. These results were consistent with other studies in Asian and global populations.

The serotype-specific prevalence of pneumococci in hospitalized pneumonia patients with COPD: a prospective, multi-center, cohort study

BACKGROUND/AIMS

The overall incidence of pneumococcal pneumonia is declining. However, the change in the pathogenic distribution of community-acquired pneumonia (CAP) in chronic obstructive pulmonary disease (COPD) patients and the serotype specificity of Streptococcus pneumoniae have not been evaluated in the post-era of pneumococcal vaccination in Korea.

METHODS

We conducted a prospective, multi-center, cohort study from seven University-affiliated hospitals. The primary objective was the identification of serotype-specific prevalence of pneumococcal pneumonia in COPD patients hospitalized for CAP. For the purpose, we conducted serotype-specific urine antigen detection (SS-UAD) assays for S. pneumoniae. The secondary objectives were other clinical characteristics of pneumonia including vaccination status.

RESULTS

The total number of participants was 349. Most of them were male (95.1%) with old ages (75.55 ± 8.59 y). The positive rate for S. pneumoniae was 9.2% with SS-UAD assay and the common serotypes were 22F, 6A, and 6B. In the sputum, Pseudomonas aeruginosa (5.0%) and Haemophilus influenzae (4.0%) were common pathogens. The vaccination rate was 78.8%, 53.0%, and 25.8% for influenza, pneumococcal polysaccharide vaccine 23 (PPV 23), and pneumococcal protein- conjugated vaccine 13 (PCV 13), respectively. Thirteen patients died during hospitalization (mortality rate; 3.7%). There was no difference in the respective rate of influenza vaccination (79.2% vs. 69.2%, p = 0.288) and PCV 13 vaccination (25.6% vs. 30.8%, p = 0.443) between survivors and the deceased.

CONCLUSION

Serotypes 22F, 6A, and 6B, which are covered either by PPV 23 or by PCV 13, are still common pneumococcal serotypes in COPD pneumonia in the post-vaccination era in Korea.

Cough Characteristics and Their Association Patterns According to Cough Etiology: A Network Analysis

Although cough is a common respiratory symptom, determining its cause is challenging. We aimed to explore how cough severity and characteristics vary with different etiologies, while investigating their interrelations with demographic features. Adult patients (n = 220) with chronic cough and completed diagnostic work-up and the COugh Assessment Test were enrolled. A correlation network analysis was used to examine the associations between the demographic features and cough severity/characteristics across various etiologies such as upper airway cough syndrome, asthma, eosinophilic bronchitis, gastroesophageal reflux disease (GERD), and idiopathic cough. Demographic features like age and sex showed complex associations with cough characteristics and severity. Cough severity decreased with age, especially in cases of eosinophilic bronchitis and GERD. Women with eosinophilic bronchitis reported more severe cough, while men with idiopathic cough reported more severe cough. Asthma was significantly linked to more sleep disturbance and fatigue, independent of age and sex, whereas GERD showed less sleep disturbance and fatigue. Network analysis revealed overall close associations between cough characteristics, though hypersensitivity in asthma and sleep disturbance in GERD were not linked with other cough traits. In conclusion, the demographic features and cough characteristics were interrelated, exhibiting distinct patterns based on the etiology.

Comparative safety of bedaquiline and delamanid in patients with multidrug resistant tuberculosis: A nationwide retrospective cohort study

BACKGROUND/PURPOSE(S)

Bedaquiline and delamanid were recently approved for multidrug resistant tuberculosis (MDR-TB). Bedaquiline carries a black box warning of increased risk of death compared to the placebo arm, and there is a need to establish the risks of QT prolongation and hepatotoxicity for bedaquiline and delamanid.

METHODS

We retrospectively analyzed data of MDR-TB patients retrieved from the South Korea national health insurance system database (2014-2020) to assess the risks of all-cause death, long QT-related cardiac event, and acute liver injury associated with bedaquiline or delamanid, compared with conventional regimen. Cox proportional hazards models were used to estimate hazard ratios (HR) with 95% confidence intervals (CI). Stabilized inverse probability of treatment weighting based on propensity score was used to balance characteristics between the treatment groups.

RESULTS

Of 1998 patients, 315 (15.8%) and 292 (14.6%) received bedaquiline and delamanid, respectively. Compared with conventional regimen, bedaquiline and delamanid did not increase risk of all-cause death at 24-month (HR 0.73 [95% CI, 0.42-1.27] and 0.89 [0.50-1.60], respectively). Bedaquiline-containing regimen increased risk of acute liver injury (1.76 [1.31-2.36]), while delamanid-containing regimen increased risk of long QT-related cardiac events (2.38 [1.05-3.57]) within 6 months of treatment.

CONCLUSION

This study adds to the emerging evidence refuting the higher mortality rate observed in the bedaquiline trial population. Association between bedaquiline and acute liver injury needs careful interpretation considering for other background hepatotoxic anti-TB drugs. Our finding on delamanid and long QT-related cardiac events suggest careful risk-benefit assessment in patients with pre-existing cardiovascular disease.

Real-world analysis of first-line afatinib in patients with EGFR-mutant non-small cell lung cancer and brain metastasis: survival and prognostic factors

Background

Overall survival (OS) in patients with non-small cell lung cancer (NSCLC) and brain metastases (BMs) is poor. We aimed to identify prognostic factors and ascertain treatment outcomes of first-line afatinib for patients with epidermal growth factor receptor (EGFR)-mutant NSCLC with BM in a real-world setting.

Methods

This retrospective observational study reviewed electronic records of patients with EGFR-mutant NSCLC who received first-line afatinib treatment between October 2014 and October 2019 in 16 hospitals across South Korea. The Kaplan-Meier method estimated time on treatment (TOT) and OS; multivariate analyses were performed using Cox proportional hazards (PH) models.

Results

Among 703 patients who received first-line afatinib, 262 (37.3%) had baseline BM. Of 441 patients without baseline BM, 92 (20.9%) developed central nervous system (CNS) failure. Compared with patients without CNS failure, those with CNS failure during afatinib treatment were younger (P=0.012), had a higher Eastern Cooperative Oncology Group (ECOG) performance status (PS) (P<0.001), increased metastatic site involvement (P<0.001), advanced stage disease (P<0.001), with liver metastasis (P=0.008) and/or bone metastasis (P<0.001) at baseline. Cumulative incidence of CNS failure in years 1, 2 and 3 was 10.1%, 21.5% and 30.0%, respectively. In multivariate analysis, cumulative incidence was significantly higher in patients with ECOG PS ≥2 (P<0.001), uncommon EGFR mutations (P=0.001), and no baseline pleural metastasis (P=0.017). Median TOT was 16.0 months (95% CI: 14.8-17.2) and, in patients with CNS failure, without CNS failure, and with baseline BM was 12.2, 18.9, and 14.1 months, respectively (P<0.001). Median OS was 52.9 months (95% CI: 45.4-60.3) and, in patients with CNS failure, without CNS failure, and with baseline BM was 29.1, 67.3 and 48.5 months, respectively (P<0.001).

Conclusions

First-line afatinib in the real-world setting showed clinically meaningful effectiveness in patients with EGFR-mutant NSCLC and BM. CNS failure was a poor prognostic factor for TOT and OS correlating with younger age, poor ECOG PS, higher metastatic number, advanced disease stage, uncommon EGFR mutations, and baseline liver and/or bone metastases.

Socioeconomic disparities and multidrug-resistant tuberculosis in South Korea: Focus on immigrants and income levels

Risk factors of MDR-TB remain unclear in South Korea, despite being an important public health issue. Findings from this study, which included ≥50,000 patients with TB from South Korea, suggests that immigrants and patients with lower income levels were strong predictors of MDR-TB in a high-income, high TB incidence country.

All-round counterattack to conquer lung cancer

Background: Lung cancer is increasing exponentially as the population ages. To conquer lung cancer, early diagnosis, developing new treatments, and combining multidisciplinary treatment modalities are essential.Current Concepts: Since the national lung cancer screening program for high-risk individuals using low-dose chest computed tomography has launched, the rate of early diagnosis of lung cancer is expected to increase. The development of immune checkpoint inhibitors and target agents is paying off in terms of producing new anticancer drugs. Immune checkpoint inhibitors are administered in combination with existing treatment modalities in various clinical situations, such as for not only patients with metastatic lung cancer but also for those with resectable lung cancer and with surgically unresectable locally advanced disease. These trials dramatically improved survival outcomes. The development of targeted anticancer drugs is also advancing at a rapid pace. The survival rate of patients with lung cancer who have specific gene mutations has greatly improved when targeted anticancer drugs are administered alone or in combination with conventional therapies.Discussion and Conclusion: Early diagnosis of lung cancer and the development of new treatment modalities are greatly improving the prognosis of patients with lung cancer. Attempts to combine conventional and new treatment modalities should continue. It is necessary to discuss changing medical policies for long-term survivors, which will inevitably increase.

Association of adverse respiratory events with sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors among patients with type 2 diabetes in South Korea: a nationwide cohort study

BACKGROUND

Impaired respiratory function remains underrecognized in patients with type 2 diabetes (T2D), despite common pulmonary impairment. Meanwhile, there is little data available on the respiratory effects of sodium glucose cotransporter 2 inhibitors (SGLT2i). Hence, we examined the association between SGLT2i use and the risk of adverse respiratory events in a real-world setting.

METHODS

We conducted a population-based, nationwide cohort study using an active-comparator new-user design and nationwide claims data of South Korea from January 2015 to December 2020. Among individuals aged 18 years or older, propensity score matching was done to match each new user of SGLT2is with dipeptidyl peptidase 4 inhibitors (DPP4is), with patients followed up according to an as-treated definition. The primary outcome was respiratory events, a composite endpoint of acute pulmonary edema, acute respiratory distress syndrome (ARDS), pneumonia, and respiratory failure. Secondary outcomes were the individual components of the primary outcome and in-hospital death. Cox models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Of 205,534 patient pairs in the propensity score matched cohort, the mean age of the entire cohort was 53.8 years and 59% were men, with a median follow-up of 0.66 years; all baseline covariates achieved balance between the two groups. Incidence rates for overall respiratory events were 4.54 and 7.54 per 1000 person-years among SGLT2i and DPP4i users, respectively, corresponding to a rate difference of 3 less events per 1000 person-years (95% CI - 3.44 to - 2.55). HRs (95% CIs) were 0.60 (0.55 to 0.64) for the composite respiratory endpoint, 0.35 (0.23 to 0.55) for acute pulmonary edema, 0.44 (0.18 to 1.05) for ARDS, 0.61 (0.56 to 0.66) for pneumonia, 0.49 (0.31 to 0.76) for respiratory failure, and 0.46 (0.41 to 0.51) for in-hospital death. Similar trends were found across individual SGLT2is, subgroup analyses of age, sex, history of comorbidities, and a range of sensitivity analyses.

CONCLUSIONS

These findings suggest a lower risk of adverse respiratory events associated with patients with T2D initiating SGLT2is versus DPP4is. This real-world evidence helps inform patients, clinicians, and guideline writers regarding the respiratory effects of SGLT2i in routine practice.

Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation-Positive Non-Small Cell Lung Cancer

PURPOSE

Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation-positive non-small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation-positive non-small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea.

MATERIALS AND METHODS

Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints.

RESULTS

A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects.

CONCLUSION

Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation-positive in Korean patients with no new safety signals.

Clinical phenotypes of chronic cough categorised by cluster analysis

BACKGROUND

Chronic cough is a heterogeneous disease with various aetiologies that are difficult to determine. Our study aimed to categorise the phenotypes of chronic cough.

METHODS

Adult patients with chronic cough were assessed based on the characteristics and severity of their cough using the COugh Assessment Test (COAT) and the Korean version of the Leicester Cough Questionnaire. A cluster analysis was performed using the K-prototype, and the variables to be included were determined using a correlation network.

RESULTS

In total, 255 participants were included in the analysis. Based on the correlation network, age, score for each item, and total COAT score were selected for the cluster analysis. Four clusters were identified and characterised as follows: 1) elderly with mild cough, 2) middle-aged with less severe cough, 3) relatively male-predominant youth with severe cough, and 4) female-predominant elderly with severe cough. All clusters had distinct demographic and symptomatic characteristics and underlying causes.

CONCLUSIONS

Cluster analysis of age, score for each item, and total COAT score identified 4 distinct phenotypes of chronic cough with significant differences in the aetiologies. Subgrouping patients with chronic cough into homogenous phenotypes could provide a stratified medical approach for individualising diagnostic and therapeutic strategies.

Temporal trends of pharmacologic treatments for tuberculosis and multidrug resistant tuberculosis following dissemination of treatment guidelines in South Korea

BACKGROUND/PURPOSE(S)

The World Health Organization (WHO) released treatment guidelines for multidrug resistant tuberculosis (MDR-TB) in 2008, with subsequent revisions in 2011; Korea disseminated corresponding guidelines in 2011 and 2014, respectively. Thus, we aimed to investigate the temporal trends of and the updated guideline's impact on the prescription patterns of anti-TB drugs.

METHODS

We conducted a time-series study using Korea's nationwide healthcare database (2007-2015), where patients with TB or MDR-TB were included. Only anti-TB drugs prescribed during the intensive phase of treatment for TB (two months) or MDR-TB (eight months) were assessed. We estimated the annual utilization of TB treatment regimens and the relative difference (RD) in the proportion of MDR-TB treatment medications between the following periods: before the first Korean guideline (June 2008 to March 2011); between the first and revised guidelines (April 2011 to July 2014); after the revised guideline (August 2014 to December 2015).

RESULTS

Of 3523 TB (mean age 54.1 years; male 56.8%) patients, treatment regimens for TB complied with guideline recommendations as >80% of patients received either quadruple (mean 66.8%) or triple (14.5%) therapy of first-line anti-TB drugs. Following the WHO's guideline update, prescription patterns changed accordingly among 111 MDR-TB (mean age 46.0 years; male 67.6%) patients, as use of pyrazinamide (RD +20.3%) and prothionamide (+11.5%) increased (recommended to be compulsory), and streptomycin (-43.1%) decreased (ototoxicity risks).

CONCLUSIONS

Anti-TB drug prescription patterns for both TB and MDR-TB well reflected WHO's treatment guideline as well as corresponding domestic guidelines of South Korea.

Clinical characteristics of patients with COVID-19 vaccine-related pneumonitis: a case series and literature review

BACKGROUND/AIMS

Pulmonary toxicities of coronavirus disease 2019 (COVID-19) vaccination are exceedingly rare. However, there are a few reported cases after mRNA vaccination, especially from Asian countries. The purpose of this study was to report the clinical characteristics of patients with COVID-19 vaccine-related pneumonitis (CV-P) and to review cases reported in the literature.

METHODS

We performed a prospective, observational case series analysis.

RESULTS

Eleven patients with a median age of 80 years were enrolled. Ten patients developed CV-P after BNT162b2-mRNA vaccination and one after ChAdOx1 nCoV-19 vaccination. We identified various patterns of CV-P, including transient infiltration, life-threatening acute respiratory distress syndrome, and aggravation of underlying interstitial lung disease. Most patients showed favorable outcomes with good responses to corticosteroid therapy.

CONCLUSION

Identifying the mechanism of CV-P requires further investigation; however, radiological and laboratory findings in our case series support inflammatory dysregulation in the lung parenchyma after vaccination. Clinicians should consider CV-P in patients with atypical lung infiltration, no specific etiologies, and recent COVID-19 vaccination.

Incidence and outcomes of adverse drug reactions to first-line anti-tuberculosis drugs and their effects on the quality of life: a multicenter prospective cohort study

BACKGROUND

In tuberculosis (TB) treatment, adverse drug reactions (ADRs) can interrupt treatment and decrease the quality of life (QoL). We aimed to prospectively investigate the incidence of ADRs to first-line anti-TB drugs and related outcomes and QoL.

METHODS

Adult patients with TB who had been treated with first-line anti-TB drugs in five Korean hospitals were enrolled. ADR questionnaire surveys and blood tests were performed four times serially, and QoL was assessed on the fourth TB treatment week (± two weeks).

RESULTS

Of 410 enrolled patients with TB (males, 62%; mean age, 52.1 ± 18.1 years [those aged ≥65 years, 26.6%]), 67.8% experienced any ADRs (≥ grade 2) to TB drugs. The most common ADR was fatigue (53.2%), followed by itching (42.7%) and anorexia (41.7%). Older adult patients experienced relatively more ADRs, including anorexia, dyspepsia, rash, dizziness, anemia, abnormal hepatic/renal function tests, and increased uric acid levels (P < 0.05). Treatment regimens changed for 9.5% of patients owing to ADRs to anti-TB drugs. Patients with any ADRs and older adult patients had significantly lower QoL than their counterparts (P < 0.05). Old age (odds ratio [OR], 1.02) and being male (OR 2.65) were independently associated with ADRs, whereas active smoking (OR 4.73) and a relatively long treatment phase (OR 5.13) were independently associated with hepatotoxicity.

CONCLUSION

ADRs to first-line anti-TB drugs were common and related to relatively low QoL, especially among older adults. Although 9.5% of patients had ADR-related regimen changes, most patients with ADRs completed treatments successfully. This article is protected by copyright. All rights reserved.

Prognostic outcome of treatment modalities for epidermal growth factor receptor-mutated advanced lung cancer

BACKGROUND/AIMS

The treatment of epidermal growth factor receptor (EGFR)-mutated lung cancer cases has shown remarkable development in the past two decades. However, there have been limited studies comparing the prognostic effects of EGFR-tyrosine kinase inhibitor (TKI) and other treatment modalities. Therefore, we compared the survival outcomes of patients treated with EGFR-TKIs versus those treated with other treatment modalities.

METHODS

Patient data were collected from the Korean National Health Insurance Database, National Health Insurance Service- National Sample Cohort 2002 to 2015, which was released by the Korean National Health Insurance Service in 2015. The lung cancer group included patients (n = 2,003) initially diagnosed with lung cancer between January 2010 and December 2013. The main outcome was all-cause mortality. A Cox proportional hazard regression analysis was used to calculate the relative risk of mortality.

RESULTS

Among the newly diagnosed lung cancer cases, 1,004 (50.1%) were included in the analysis. A 15.1-month median survival benefit was observed in the EGFR-TKI group than that of the multimodality therapy group. The risk of mortality was as follows: EGFR-TKI treatment group (n = 142; hazard ratio [HR], 5.29; 95% confidence interval [CI], 3.57 to 7.86) and multimodality therapy group (n = 326; HR, 7.42; 95% CI, 5.19 to 10.63) compared to surgery only (n = 275).

CONCLUSION

Patients with advanced lung cancer harbouring EGFR mutations treated with EGFR-TKIs showed better median survival and lower risk of mortality than those in the multimodality therapy group. In the case of EGFR-mutated advanced lung cancer, there is room for downstaging in the TNM classification.

Associations Between Asthma Diagnosis/Asthma Exacerbation and Previous Proton-Pump Inhibitor use: A Nested Case-Control Study Using a National Health Screening Cohort

Background: Proton-pump inhibitors (PPIs) block acid secretion from gastric parietal cells; however, recent studies have reported that PPIs have antioxidant and anti-inflammatory properties in various cells. Newer PPIs are stronger inhibitors of acid secretion; however, the anti-inflammatory effects of these drugs have not been assessed. We evaluated anti-inflammatory effect of PPIs on the development of asthma/asthma exacerbation (AE) in a national health screening cohort.

Methods: This case-control study comprised 64,809 participants with asthma who were 1:1 matched with controls from the Korean National Health Insurance Service-Health Screening Cohort. Conditional logistic regression analysis was used to evaluate the effect of previous PPI use on an asthma diagnosis in all participants. Unconditional logistic regression was used to assess the effect of PPI use on AE in participants with asthma. These relationships were estimated in a subgroup analysis according to PPI generation.

Results: Overall, PPI use increased the risk of asthma diagnosis [adjusted odds ratio (aOR) = 1.29, 95% confidence interval (CI) = 1.23–1.35, p < 0.001]. Use of the first-generation PPIs was associated with asthma (aOR = 1.34, 95% CI = 1.18–1.52, p < 0.001), while use of second-generation PPIs was not (aOR = 0.97, 95% CI = 0.82–1.15, p = 0.748). In contrast, overall PPI use decreased the risk of AE in participants with asthma (aOR = 0.79, 95% CI = 0.75–0.84, p < 0.001), although this effect was observed only for second-generation PPIs (aOR = 0.76, 95% CI = 0.65–0.89, p = 0.001).

Conclusion: PPI use increased the risk for subsequent asthma diagnosis. However, this effect was confined to first-generation PPIs. Second-generation PPIs decreased the risk of AE.

The Influence of Prior Statin Use on the Prevalence and Exacerbation of Chronic Obstructive Pulmonary Disease in an Adult Population

Background

Statins have anti-inflammatory and antioxidant properties, and previous studies have reported the positive effects of statins on chronic obstructive pulmonary disease (COPD) outcomes. However, the effects of statins on the development and acute exacerbations of COPD remain unclear. Therefore, this study aimed to assess the relation between statin use and COPD occurrence in all participants and the link between statin use and COPD acute exacerbations in participants with COPD.

Methods

This case-control study comprised 26,875 COPD participants and 107,500 control participants who were 1:4 matched from the Korean National Health Insurance Service-Health Screening Cohort. Conditional logistic regression was used to evaluate the probability of COPD occurrence associated with previous statin use. In addition, unconditional logistic regression was employed to assess the risk of exacerbations related to statin use among COPD participants. These relations were estimated in subgroup analysis according to statin type (lipophilic vs. hydrophilic).

Results

The association between previous statin use and the occurrence of COPD did not reach statistical significance in the overall population (adjusted odds ratio [aOR] = 0.96, 95% confidence interval [CI] = 0.93–1.00, P = 0.059). However, statin use decreased the probability of exacerbations in participants with COPD (aOR = 0.79, 95% CI = 0.74–0.85, P &lt; 0.001). Lipophilic statins decreased the probability of exacerbations, whereas hydrophilic statins were not associated with a decreased likelihood of exacerbations (aOR = 0.78, 95% CI = 0.72–0.84, P &lt; 0.001 for lipophilic statins; aOR = 0.89, 95% CI = 0.78–1.02, P = 0.102 for hydrophilic statins).

Discussion

Statin use was not associated with the occurrence of COPD in the adult population. However, statin use was associated with a reduced probability of exacerbations in participants with COPD, with a greater risk reduction with lipophilic statin use.

Pretreatment neutrophil-to-lymphocyte ratio and cigarette smoking as prognostic factors in patients with advanced NSCLC treated with osimertinib

Background

The remarkable efficacy of osimertinib in non‒small cell lung cancer (NSCLC) with acquired T790M mutation has been widely documented in clinical trials and real-world practice. However, some patients show primary resistance to this drug. Even patients who initially show a favorable response have inconsistent clinical outcomes later. Therefore, the aim of this study was to identify additional clinical predictive factors for osimertinib efficacy.

Methods

A prospective cohort of patients with acquired T790M positive stage IV lung adenocarcinoma treated with osimertinib salvage therapy in Hallym University Medical Center were analyzed.

Results

Sixty-one eligible patients were analyzed, including 38 (62%) women and 39 (64%) who never smoked. Their mean age was 63.3 years. The median follow-up after treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) was 36.0 months (interquartile range, 24.7–50.2 months). The majority (n=45, 74%) of patients were deceased. Based on univariate analysis, low baseline neutrophil-to-lymphocyte ratios (NLR), age ≥50 years, never-smoking history, stage IVA at osimertinib initiation, and prolonged response to previous TKIs (≥10 months) were associated with a significantly longer progression-free survival (PFS). Multivariate analysis showed that never-smoking status (hazard ratio [HR], 0.54; 95% confidence interval [CI], 0.30–0.98; p=0.041) and a baseline NLR less than or equal to 3.5 (HR, 0.23; 95% CI, 0.12–0.45; p<0.001) were independently associated with a prolonged PFS with osimertinib.

Conclusion

Smoking history and high NLR were independent negative predictors of osimertinib PFS in patients with advanced NSCLC developing EGFR T790M resistance after the initial EGFR-TKI treatment.

Korean physician prescription patterns for home oxygen therapy in chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Hypoxemia in chronic obstructive pulmonary disease (COPD) leads to reduced ability to exercise, decreased quality of life, and, eventually, increased mortality. Home oxygen therapy in patients with severe COPD reduces distress symptoms and mortality rates. However, there have been few studies on physicians' prescription behavior toward home oxygen therapy. Therefore, we investigated the respiratory specialists' perspective on home oxygen therapy.

METHODS

In this cross-sectional, study, a questionnaire was completed by 30 pulmonary specialists who worked in tertiary hospitals and prescribed home oxygen therapy. The questionnaire consisted of 28 items, including 15 items on oxygen prescription for outpatients, four for inpatients, and nine on service improvement.

RESULTS

All physicians were prescribing less than 2 L/min of oxygen for either 24 (n = 10, 33.3%) or 15 hours (n = 9, 30.3%). All (n = 30) used pulse oximetry, 26 (86.7%) analyzed arterial blood gas. Thirteen physicians had imposed restrictions and recommended oxygen use only during exercise or sleep. Sixteen (53.3%) physicians were educating their patients about home oxygen therapy. Furthermore, physicians prescribed home oxygen to patients that did not fit the typical criteria for long-term oxygen therapy, with 30 prescribing it for acute relief and 17 for patients with borderline hypoxemia.

CONCLUSION

This study identified the prescription pattern of home oxygen therapy in Korea. Respiratory physicians prescribe home oxygen therapy to hypoxemic COPD patients for at least 15 hours/day, and at a rate of less than 2 L/min. More research is needed to provide evidence for establishing policies on oxygen therapy in COPD patients.

Voluntary running attenuates behavioural signs of low back pain: dimorphic regulation of intervertebral disc inflammation in male and female SPARC-null mice

OBJECTIVE

To examine the effect of running exercise on behavioral measures of pain and intervertebral disc (IVD) inflammation in the SPARC-null mouse model.

METHODS

Male and female 8-month old SPARC-null and age-matched control mice received a home cage running wheel or a control, fixed wheel for 6 months. Behavioral assays were performed to assess axial discomfort (grip test) and radiating leg pain (von Frey, acetone tests) and voluntary running was confirmed. Expression of inflammatory mediators (TNF-α, IL-1β, IL-2, IL-10, CCL5, CXCL1, CXCL5, RANKL, M-CSF, and VEGF) in IVDs was determined. Additional inflammatory (IL-1β, IL-1Ra, CXCR1, CXCR2) and macrophage phenotypic markers (ITGAM, CD80, CD86, CD206, Arg1) in IVDs were investigated by qPCR.

RESULTS

Voluntary running attenuated behavioral measures of pain in male and female SPARC-null mice. Increases in mediators including IL-1β, CXCL1 and CXCL5 were observed in SPARC-null compared to control IVDs. After 6 months of running, increases in M-CSF and VEGF were observed in male SPARC-null IVDs. In females, pro-inflammatory mediators, including CXCL1 and CXCL5 were downregulated by running in SPARC-null mice. qPCR analysis further confirmed the anti-inflammatory effect of running in female IVDs with increased IL-1Ra mRNA. Running induced upregulation of the macrophage marker ITGAM mRNA in males.

CONCLUSIONS

Voluntary running reversed behavioral signs of pain in male and female mice and reduced inflammatory mediators in females, but not males. Thus, the therapeutic mechanism of action may be sex-specific.

Multicenter real-world data of patients harboring rare mutations other than EGFR or ALK in advanced or metastatic non-small cell lung cancer

Background

Studies on the application of targeted therapies for patients with non‐small cell lung cancer (NSCLC) who harbor rare genetic mutations are ongoing. In the present study, we investigated the real‐world data of NSCLC patients who harbor rare mutations.

Methods

We retrospectively analyzed patients with advanced or metastatic nonsquamous NSCLC aged >20 years with confirmed rare mutations (BRAF, ROS1, MET, RET, HER2, FGFR, and NTRK) from January 2015 to September 2020 at nine tertiary hospitals. In addition, we validated the lung cancer PCR panel kit in patients with confirmed mutations by NGS.

Results

Among 118 patients included, 88 received platinum‐based chemotherapy as first‐line chemotherapy. The progression‐free survival of patients with BRAF, ERBB2, MET, RET, and ROS1 mutations was 10.9 months (95% confidence interval [CI]: 1.3–20.5), 5.3 months (95% CI: 3.0–7.5), 7.2 months (95% CI: 3.6–10.9), 11.4 months (95% CI: 9.2–13.6), and 10.0 months (95% CI: 3.7–16.4) respectively (p = 0.041). The median overall survival (OS) was not reached in patients with ROS1 mutations; however, in BRAF, ERBB2, MET, and RET mutant patients, median OS was 14.1 months (95% CI: 10.1–14.1), 34.5 months (95% CI: 13.2–36.9), 22.7 months (95% CI: 1.7–24.0), and 29.8 months (95% CI: 28.9–61.3), respectively (p = 0.006). Of the 27 tissue samples, 26 (96.3%) showed the same PCR panel kit result with NGS.

Conclusions

First‐line platinum‐based chemotherapy showed durable benefit in patients with advanced or metastatic nonsquamous NSCLC harboring rare genetic mutation other than EGFR or ALK.

Risk-based prediction model for selecting eligible population for lung cancer screening among ever smokers in Korea

Background

This study developed a new lung cancer risk prediction model for the Korean population and evaluated the performance, compared to the previously reported risk models developed in Western countries.

Methods

Among the 6,811,893 people who received health examinations from the Korean National Health Insurance Service, 969,351 ever-smokers (40–79 years) were included. Performance of Bach, Lung Cancer Risk Models for Screening, PLCOM2012, Pittsburgh, and Liverpool Lung Project models were evaluated. The ever-smokers were divided into the training and validation datasets by random sampling. The lung cancer risk model was developed and validated in the Korean population. The efficiency of model-based selection for lung cancer screening was compared with the eligible criteria of the National Lung Screening Trial (NLST).

Results

The Korean lung cancer risk model showed the area under the curve and expected/observed (E/O) ratio of 0.816 and 0.983 in the training dataset and 0.816 and 0.988 in the validation dataset. The Korean lung cancer risk model included age-mean of age, square of age-mean of age, sex, square root of pack-years of smoking, years since cessation, physical activity, alcohol consumption, body mass index, and medical history of chronic pulmonary obstructive disease, emphysema, pneumoconiosis, and interstitial pulmonary disease. Compared with the NLST criteria, the Korean lung cancer risk model’s cut-off criteria (>2.1%) had more improved sensitivity (61.4% vs. 44.3%) and positive predictive value (4.1% vs. 2.9%). The Korean lung cancer risk model showed better discrimination and calibration than previously developed models in Western population.

Conclusions

The Korean lung cancer risk model can select eligible population for low-dose computed tomography screening among the Asian population. The efficiency of risk model-based selection for lung cancer screening is superior to that of fixed criteria-based selection.

Impact of COVID-19 on TB epidemiology in South Korea

SETTING: Five referral hospitals, South Korea.OBJECTIVE: To assess epidemiological changes in TB before and during the COVID-19 pandemic.DESIGN: This was a multicentre cohort study of 3,969 patients diagnosed with TB.RESULTS: We analysed 3,453 patients diagnosed with TB prior to the COVID-19 pandemic (January 2016-February 2020) and 516 during the pandemic (March-November 2020). During the pandemic, the number of patients visits declined by 15% from the previous 4-year average, and the number of patients diagnosed with TB decreased by 17%. Patients diagnosed during the pandemic were older than those diagnosed before the pandemic (mean age, 60.2 vs. 56.6 years, P < 0.001). The proportion of patients to have primary TB at a younger age (births after 1980) among those diagnosed with TB was significantly lower during the pandemic than before (17.8% in 2020 vs. 23.5% in 2016, 24.0% in 2017, 22.5% in 2018, 23.5% in 2019; P = 0.005).CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of visits to respiratory departments, leading to fewer patients being diagnosed with TB. However, our results suggest that universal personal preventive measures help to suppress TB transmission in regions with intermediate TB burden.

Changes in respiratory virus infection trends during the COVID-19 pandemic in South Korea: the effectiveness of public health measures

BACKGROUND/AIMS

Studies on the effectiveness of public health measures to prevent respiratory virus transmission in real-world settings are lacking. We investigated the effectiveness of universal mask use and adherence to other personal preventive measures on the changing viral respiratory infection patterns during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

Data were extracted from the South Korean National Respiratory Virus Sentinel Surveillance System. During the COVID-19 pandemic, a cross-sectional survey on adherence to personal preventive measures was conducted. Additionally, the number of subway passengers was analyzed to estimate physical distancing compliance.

RESULTS

During the pandemic, adherence to personal preventive measures significantly increased, particularly indoors and on public transportation. Respiratory virus trends were compared based on laboratory surveillance data of 47,675 patients with acute respiratory infections (2016 to 2020). The 2019 to 2020 influenza epidemic ended within 3 weeks, from the epidemic peak to the epidemic end, quickly ending the inf luenza season; with a 1.8- to 2.5-fold faster decline than in previous seasons. Previously, the overall respiratory virus positivity rate remained high after the influenza seasons had ended (47.7% to 69.9%). During the COVID-19 pandemic, this positive rate, 26.5%, was significantly lower than those in previous years. Hospital-based surveillance showed a decreased number of hospitalized patients with acute viral respiratory illnesses.

CONCLUSION

This study suggests that high compliance to the use of personal preventive measures in public might reduce the incidence of all respiratory virus infections and its hospitalization rates, with no additional quarantine, isolation, or contact screening.

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

Sequential treatment of afatinib and osimertinib or other regimens in patients with advanced non-small-cell lung cancer harboring EGFR mutations: Results from a real-world study in South Korea

OBJECTIVES

The optimal sequence for the administration of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for treating non-small cell lung cancer (NSCLC) is still unclear. This study aimed to evaluate the efficacy of sequential afatinib and osimertinib treatment in patients with NSCLC harboring EGFR mutations.

MATERIALS AND METHODS

Electronic records of patients with EGFR-mutated NSCLC, who were administered afatinib and osimertinib (group A) or other chemotherapy (group B) between October 2014 and 2019, across 16 hospitals in South Korea were reviewed. The primary outcome, time on treatment (TOT), secondary outcome, and overall survival (OS) were estimated using the Kaplan-Meier method and log-rank test. Multivariate analyses were performed using the Cox proportional hazards model.

RESULTS

Of the 737 patients who received frontline afatinib treatment, 324 with complete records were selected (group A: 126, group B: 198). All patients in group A were T790M positive after afatinib, while patients in group B were all negative or unknown. The median TOT was 35.4 months (95% confidence interval [CI]: 27.7-45.6) in group A and 20.8 months (95% CI: 19.4-24.0) in group B. The median TOT with afatinib was 13.0 months (95% CI: 12.0-13.9) overall and 15.7 months (95% CI: 13.9-17.3) in group A. The 2- and 3-year survival rates were 86.0 and 69.3% in group A and 75.9 and 55.3% in group B, respectively.

CONCLUSION

Sequential afatinib and osimertinib treatment resulted in better survival rates than treatment with afatinib followed by other chemotherapies.

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.

Revised Korean Cough Guidelines, 2020: Recommendations and Summary statements

Cough is the most common respiratory symptom that can have various causes. It is a major clinical problem that can reduce a patient’s quality of life. Thus, clinical guidelines for the treatment of cough were established in 2014 by the cough guideline committee under the Korean Academy of Tuberculosis and Respiratory Diseases. From October 2018 to July 2020, cough guidelines were revised by members of the committee based on the first guidelines. The purpose of these guidelines is to help clinicians efficiently diagnose and treat patients with cough. This article highlights the recommendations and summary of the revised Korean cough guidelines. It includes a revised algorithm for the evaluation of acute, subacute, and chronic cough. For a chronic cough, upper airway cough syndrome (UACS), cough variant asthma (CVA), and gastroesophageal reflux disease (GERD) should be considered in differential diagnoses. If UACS is suspected, first-generation antihistamines and nasal decongestants can be used empirically. In cases with CVA, inhaled corticosteroids are recommended to improve cough. In patients with suspected chronic cough due to symptomatic GERD, proton pump inhibitors are recommended. Chronic bronchitis, bronchiectasis, bronchiolitis, lung cancer, aspiration, intake of angiotensin-converting enzyme inhibitor, intake of dipeptidyl peptidase-4 inhibitor, habitual cough, psychogenic cough, interstitial lung disease, environmental and occupational factors, tuberculosis, obstructive sleep apnea, peritoneal dialysis, and unexplained cough can also be considered as causes of a chronic cough. Chronic cough due to laryngeal dysfunction syndrome has been newly added to the guidelines.

Association Between Statin Medication and Asthma/Asthma Exacerbation in a National Health Screening Cohort

BACKGROUND

Statins, which are a type of 3-hydroxy-3-methylglutaryl-CoA inhibitor, have multiple therapeutic effects, including anti-inflammatory and immunomodulatory properties. Despite positive preclinical data on statin use in patients with asthma, clinical trials and epidemiological studies have yielded conflicting results.

OBJECTIVE

To evaluate the association between statin use and an asthma diagnosis in all participants and the effects of statins on asthma-related outcomes among patients with asthma using a national health screening cohort.

METHODS

Patients with asthma and control participants matched for age group, sex, income, and region of residence were selected from the Korean National Health Insurance Service-Health Screening Cohort data. This case-control study comprised 88,780 people with asthma and the same number of control participants. Asthma exacerbation (AE) was defined as an emergency department visit, a history of hospitalization due to asthma, or the use of systemic steroids for 2 weeks. Conditional and unconditional logistic regression analyses were used to evaluate the effect of the previous use of statins on an asthma diagnosis or AE after adjusting for multiple covariates.

RESULTS

A significant association between a statin prescription and an asthma diagnosis was not observed in this cohort (adjusted odds ratio, 1.01; 95% CI, 0.98-1.03; P = .633 for 1 year of statin prescription). Among the patients with asthma, 16.54% (n = 14,687) were categorized into the AE group and the others (n = 74,093) were categorized into the no AE group. A statin prescription was associated with fewer AEs in patients with asthma (adjusted odds ratio, 0.89; 95% CI, 0.84-0.93; P < .001 for 1 year of statin prescription).

CONCLUSIONS

Statin use was associated with a reduced risk of asthma-related emergency department visits, hospitalizations, and systemic steroid use in patients with asthma in this cohort study.

Epidemiology and clinical features of common community human coronavirus disease

Background

We would evaluate the epidemiology, clinical aspects, and prognostic factors of patients of all ages admitted with human corona virus (HCoV).

Methods

This study was retrospectively performed at five university teaching hospitals between 1st January 2018 and 31th March 2020. Routine molecular testing using for multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) methods was conducted on the respiratory viruses. We assessed the demographics, laboratory findings, and treatment of patients infected with coronavirus.

Results

There were 807 coronavirus-infected patients from 24,311 patients with respiratory virus PCR test admitted to five hospitals over 27 months. All-cause mortality rates of patients admitted for seasonal HCoV disease were 3.1% in all patients and 10.8% in patients aged ≥18 years. The Cox proportional hazard regression analysis was performed in patients aged ≥18 years. After adjusting for other clinical variables, general weakness symptoms [hazard ratio (HR), 2.651; 95% confidence interval (CI), 1.147-6.125, P=0.023], National Early Warning Score (NEWS) ≥2 (HR, 5.485; 95% CI, 1.261-23.858, P=0.023), and coronavirus subtype OC43 (HR, 2.500; 95% CI, 1.060-5.897, P=0.036) were significantly associated with death from coronavirus.

Conclusions

Coronavirus infection can reveal a higher mortality rate in patients of ≥18 than those of <18 years, thus, adult patients require more careful treatment. Furthermore, in adult patients, the factors associated with death from coronavirus include general weakness symptoms, NEWS higher than 2, and OC43 subtype.

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.

Adherence and Associated Factors of Treatment Regimen in Drug-Susceptible Tuberculosis Patients

Background: Adherence to tuberculosis (TB) drugs is one of the key aspects of global TB control, yet there is a lack of epidemiological evidence on the factors influencing adherence to TB drugs. Thus, this study aimed to explore the adherence and factors associated with adherence among TB patients in South Korea. Methods: We conducted a cohort study using a sampled national healthcare database from 2017 to 2018. Our study population included incident TB patients initiating quadruple or triple regimen who were available for follow-up for 180-days. Adherence was evaluated using the proportion of days covered (PDC): 1) adherent group: patients with PDC ≥80%; 2) non-adherent group: patients with PDC <80%. Kaplan-Meier analysis was conducted to calculate the median time-to-discontinuation in the study population. We calculated the adjusted odds ratios (aOR) with 95% confidence intervals (CI) to assess factors associated with adherence to TB drugs using logistic regression. Results: Of 987 patients, 558 (56.5%) were adherent and 429 (43.5%) were non-adherent, with the overall mean PDC of 68.87% (standard deviation, 33.37%). The median time-to-discontinuation was 113 days (interquartile range 96-136) in the study population. Patients initiating quadruple regimen were more likely to adhere in comparison to the triple regimen (aOR 4.14; 95% CI 2.78-6.17), while those aged ≥65 years (aOR 0.53; 95% CI 0.35-0.81), with a history of dementia (aOR 0.53; 95% CI 0.34-0.85), and with history of diabetes mellitus (aOR 0.70; 95% CI 0.52-0.96) were less likely to adhere to the drug. Conclusion: Approximately 45% of TB patients were non-adherent to the drug, which is a major concern for the treatment outcome. We call for intensified attention from the authorities and healthcare providers to reinforce patients' adherence to the prescribed TB drugs.

Clinical impact of rebiopsy among patients with epidermal growth factor receptor-mutant lung adenocarcinoma in a real-world clinical setting

Background

In this study, we investigated the risk factors of acquired T790M mutation among patients with lung adenocarcinoma with epidermal growth factor receptor (EGFR) tyrosine mutation who were treated with EGFR‐tyrosine kinase inhibitors (TKIs). The aim was to identify the clinical impact of rebiopsy.

Methods

This multicenter, retrospective cohort study was conducted in South Korea from January 2007 to June 2017. Patients with adenocarcinoma with EGFR mutation who underwent rebiopsy and were treated with EGFR‐TKIs were included.

Results

Of a total of 352 patients, T790M mutation was identified in 156 (41.9%) at the time of rebiopsy. The median duration from initial biopsy to rebiopsy was 17 months. Univariate logistic regression analysis revealed associations of exon 19 deletion (odds ratio [OR], 1.643; p = 0.026), absence of L858R (OR, 0.627; p = 0.042), and previous EGFR‐TKI treatment duration (OR, 1.039; p < 0.001) with T790M mutation. Previous EGFR‐TKI treatment duration (OR, 3.580; p < 0.001) was independently associated with T790M mutation. A multivariate Cox proportional hazard model revealed that brain metastasis at initial diagnosis (hazard ratio, 1.390; p = 0.050) tended to be associated with T790M mutation. Among the patients with T790M mutation at rebiopsy, the osimertinib user group (n = 90) had a better one‐year survival (68.7 vs. 58.3%, p = 0.048) than the osimertinib nonuser group (n = 66).

Conclusions

Rebiopsy might affect the clinical course of patients with EGFR‐mutant adenocarcinoma who receive EGFR‐TKIs.

Feasibility of implementing a national lung cancer screening program: Interim results from the Korean Lung Cancer Screening Project (K-LUCAS)

Background

Lung cancer screening conducted in high-risk group using low-dose computer tomography (LDCT) has been reported as an effective method to reduce lung cancer mortality in two large randomized-control trials. However, the effectiveness is uncertain when lung cancer screening is expanded to a nationwide population-based program.

Methods

The Korean Lung Cancer Screening Project (K-LUCAS) is a single-arm cohort study that was conducted from February 2017 to evaluate the feasibility of implementing an organized national lung cancer screening program in Korea. High-risk population aged 55–74 years with more than a 30-pack-year smoking history was recruited. Smoking history was obtained from administering questionnaires at national health screening programs or public smoking cessation programs which are already established programs in Korea. The screening results were reported using the Lung Imaging Reporting and Data System (Lung-RADS), suggested by the American College of Radiology. K-LUCAS was performed by a network-based diagnosis supporting system using a computer-aided detection (CAD) program to maintain screening quality. Current smokers were provided with mandatory smoking counseling.

Results

Among 71,829 participants aged 50 years or older in the national health screening program, 5,975 (8.3%) were eligible for lung cancer screening. Among them, 1,062 (17.8%) refused to participate in K-LUCAS. Additionally, 779 participants were recruited in the smoking cessation program. Thus, a total of 5,692 eligible high-risk participants were recruited in this study. Among them, 865 (15.2%) had positive screening results, which requires a further examination; 529 (9.3%) had Lung-RADS category 3 (indeterminate), and 336 (5.9%) had category 4 (suspicious of lung cancer); 42 (0.7%) had confirmed lung cancer. Approximately 66.7% had early-stage lung cancer: 24 (57.1%), stage I and 4 (9.5%), stage II. Six (1.1%) patients developed complications at the time of diagnosis, including one death. The anxiety level related to cancer screening was low. Participation in screening encouraged motivation to quit smoking.

Conclusions

K-LUCAS provided promising evidence supporting the implementation of a national lung cancer screening program to detect early stage lung cancer and promote smoking cessation for participants in Asian population.

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.

Specific Antibody Deficiency in Adult Patients With IgG or IgG Subclass Deficiency

Purpose

Specific antibody deficiency (SAD) involves a deficient response to a polysaccharide vaccine despite having normal immunoglobulin levels. The failure of the polysaccharide response can be observed as a component of various primary antibody deficiencies. However, only a few studies have described the clinical and immunological profiles in SAD and/or other primary immunodeficiencies (PIDs) in adults.

Methods

A total of 47 patients who had a clinical history suggestive of antibody deficiency or had already been diagnosed with various antibody deficiencies were enrolled. Polysaccharide responses to 7 pneumococcal serotypes (4, 6B, 9V, 14, 18C, 19F and 23F) were measured using the World Health Organization enzyme-linked immunosorbent assay (WHO-ELISA), and postvaccination immunoglobulin G (IgG) titers were compared to clinical and laboratory parameters.

Results

Based on the American Academy of Allergy, Asthma, and Immunology (AAAAI) criteria for the WHO-ELISA, 11 (23.4%) patients were diagnosed as having SAD. Sixteen-three percent of them had combined with other types of PID, such as IgG subclass deficiency and hypogammaglobulinemia. Postvaccination IgG titers for the serotypes 4/9V/18C correlated with IgG2 (P = 0.012, P = 0.001, and P = 0.004) and for 6B/9V/14 with IgG3 (P = 0.003, P = 0.041, and P = 0.036, respectively). The IgG3 subclass levels negatively correlated with forced expiratory volume in 1 second (FEV1, %) and FEV1/forced vital capacity (P < 0.001 and P = 0.001, respectively).

Conclusion

SAD can be diagnosed in patients with normal IgG levels as well as in those deficient in IgG or the IgG3 subclass, implicating that restricted responses to Streptococcus pneumoniae polysaccharide antigens commonly exist in patients with predominantly antibody deficiency.

Sex Difference and Smoking Effect of Lung Cancer Incidence in Asian Population

Simple Summary

This study analyzed the sex difference in the effect of smoking exposure on lung cancer in terms of absolute and relative risks despite the increasing lung cancer incidence in Asian female never smokers. Lung cancer risk is positively associated with the duration of smoking, quantity of smoking, and pack-years of smoking, and negatively associated with the number of years since smoking cessation for both sexes. However, higher lung cancer incidence in men than in women with the same level of smoking exposure was observed, suggesting a higher susceptibility for lung cancer in men. Sex should be considered in combination with smoking history in the selection of a lung cancer screening target population.

Abstract

This study analyzed the sex difference in the effect of smoking exposure on lung cancer in terms of absolute and relative risks despite the increasing lung cancer incidence in Asian female never smokers. A retrospective cohort study was conducted on individuals aged 40–79 years who participated in the national health screening program in 2007 and 2008 with linkage to the Korea Central Cancer Registry records. We evaluated sex differences in the age-standardized incidence rate (ASR) of lung cancer by smoking history and the hazard ratio (HR) after adjusting for potential confounders. ASRs for male and female never smokers were 92.5 and 38.3 per 100,000 person-years, respectively (rate ratio (RR) = 2.4; 95% confidence interval (CI) = 2.3–2.5). ASRs for male and female current smokers with a 30 pack-year smoking history were 305.3 and 188.4 per 100,000 person-years, respectively (RR = 1.6; 95% CI = 1.3–2.0). Smoking was significantly associated with lung cancer risk for both sexes. HRs for former smokers versus never smokers were 1.27 (95% CI = 1.23–1.33) for men and 1.43 (95% CI = 1.16–1.81) for women. HRs for current smokers versus never smokers were 2.71 (95% CI = 2.63–2.79) for men and 2.70 (95% CI = 2.48–2.94) for women. HRs for lung cancer increased similarly in both men and women according to smoking status. However, among Korean individuals with comparable smoking statuses, lung cancer incidence is higher in men than in women. Sex should be considered in combination with smoking history in the selection of a lung cancer screening target population.

Awareness and Use of Complementary and Alternative Medicine in Korean Lung Cancer Patients

Background

Complementary and alternative medicine (CAM) has been used frequently, and its use continues to increase in lung cancer patients, despite insufficient scientific of its efficacy. To investigate this situation, we analyzed the current awareness and use of CAM in Korean lung-cancer patients.

Methods

This prospective survey–based study was performed at seven medical centers in South Korea between August and October 2019. The survey assessed general patient characteristics and the awareness and use of CAM. We analyzed differences in the clinical parameters of patients aware and not aware of CAM and of CAM non-users and users.

Results

Of the 434 patients included in this study, 68.8% responded that they were aware of CAM and 30.9% said they had experienced it. In univariate analysis, the patients aware of CAM were younger with poor performance status, had advanced-stage lung cancer, received more systemic therapy, and received concurrent chemoradiation therapy (CCRT). By multiple logistic regression, younger age, poor performance status, advanced stage, and prior CCRT were identified as independent risk factors for CAM awareness. There were no significant differences in the general characteristics and cancer-associated clinical parameters of CAM non-users and users.

Conclusion

Specific clinical parameters were associated with patients’ awareness of CAM, although there were no significantly different characteristics between CAM users and non-users.

Brain natriuretic peptide levels predict 6-month mortality in patients with cardiogenic shock who were weaned off extracorporeal membrane oxygenation

There are limited data regarding the association between brain natriuretic peptide (BNP) levels obtained after weaning from extracorporeal membrane oxygenation (ECMO) and the outcomes of patients with acute coronary syndrome (ACS)-associated cardiogenic shock.We prospectively obtained data regarding patients (aged ≥ 19 years) with ACS-associated cardiogenic shock who received ECMO and were subsequently weaned off the treatment. BNP levels were collected at 5 time points: pre-ECMO implantation, post-ECMO implantation, pre-ECMO weaning, day 1 after ECMO weaning, and day 5 after ECMO weaning.Of 48 patients with ACS-related cardiogenic shock, 33 were included in this analysis. Mean patient age was 59.0 (50.0-66.5) years, and 5 patients (15.2%) were women. Eight patients had asystole/pulseless electrical activity before ECMO and 14 (42.4%) had 3-vessel disease on coronary angiography. During the 6-month follow up, 12 (36.4%) patients died. BNP levels after ECMO weaning were significantly different between 6-month survivors and non-survivors. Cox proportional hazards model revealed that BNP levels (tertiles) on days 1 and 5 after ECMO weaning were significantly associated with 6-month mortality (hazard ratio, 7.872; 95% confidence interval, 1.870-32.756; 8.658 and 1.904-39.365, respectively). According to the Kaplan-Meier curves, the first tertile had significantly longer survival compared to the third tertile for both days 1 and 5 after ECMO weaning.Post-ECMO weaning BNP levels (days 1 and 5) were significantly associated with increased 6-month mortality in patients with ACS complicated by refractory cardiogenic shock who were weaned off ECMO.

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.

Metformin and tuberculosis risk in elderly patients with diabetes mellitus

SETTING: Tuberculosis (TB) and diabetes mellitus (DM) remain global health concerns. Metformin has recently received attention for its anti-tuberculosis effects.OBJECTIVE: To evaluate the risk of TB development in elderly DM patients treated with metformin compared with sulfonylureas.DESIGN: We performed a retrospective cohort study using the National Health Insurance Service-Senior database. The participants were type-2 DM (T2DM) patients aged ≥60 years between 1 January 2003 and 31 December 2013. We matched each metformin user to a sulfonylurea user using a propensity score. A Cox proportional hazards model was used to compare the risk of TB in metformin and sulfonylurea users.RESULTS: After propensity score matching, 12,582 patients were in each group. The TB incidence was 280.2/100 000 person-years (py) for metformin users and 394.5/100 000 py for sulfonylurea users. Metformin users had a lower risk of TB development than sulfonylurea users (adjusted hazard ratio 0.74, 95%CI 0.58-0.95), and the results were stronger for male participants. A dose-response relationship between metformin use and TB development was found in both sexes.CONCLUSION: Metformin use was associated with a decreased risk of TB development among elderly T2DM patients compared with sulfonylurea use.