Search

This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively. Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques. There has been a decrease in intravenous thrombolysis rates, from 12% in 2017-2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for non-cardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

In the 2023-2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, -51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: In Korea, there are no surveillance programs for vaccines that are not included in the national immunization program (NIP), and vaccine safety monitoring in the adult population is inadequate. This study aimed to establish a safety monitoring system for non-NIP vaccines in adults., Methods: Frequently administered non-NIP vaccines were selected. Individuals were included if they received at least one of the selected vaccines at a participating institution and provided informed consent. Solicited and unsolicited adverse events were monitored using questionnaires sent through text messages on days 1, 3, 7, 28, and 90 post-vaccination. Selected adverse events of special interest (AESIs) were monitored monthly by retrospective review of electronic medical records. Causality was assessed according to the Korea Disease Control and Prevention Agency guidelines., Results: Four vaccines (tetanus-diphtheria-pertussis [Tdap], pneumococcal conjugate 13-valent [PCV13], live zoster vaccine [ZVL], and recombinant zoster vaccine [RZV]) were selected, and their safety profiles were monitored at four tertiary hospitals and 10 primary care clinics. The response rates of the questionnaires on post-vaccination days 1, 7, 28, and 90 were 99.2%, 93.6%, 81.0%, and 48.7%, respectively. Of 555 AESI identified over 10 months, 10 cases received one of the selected non-NIP vaccines within 90 days of the event., Conclusion: We are establishing the first safety monitoring system for selected non-NIP vaccines in Korea since September 2022 and report its progress as of July 2023. However, continuous government support is essential for its maintenance and improvement., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: Worldwide, sepsis is the leading cause of death in hospitals. If mortality rates in patients with sepsis can be predicted early, medical resources can be allocated efficiently. We constructed machine learning (ML) models to predict the mortality of patients with sepsis in a hospital emergency department., Methods: This study prospectively collected nationwide data from an ongoing multicenter cohort of patients with sepsis identified in the emergency department. Patients were enrolled from 19 hospitals between September 2019 and December 2020. For acquired data from 3,657 survivors and 1,455 deaths, six ML models (logistic regression, support vector machine, random forest, extreme gradient boosting [XGBoost], light gradient boosting machine, and categorical boosting [CatBoost]) were constructed using fivefold cross-validation to predict mortality. Through these models, 44 clinical variables measured on the day of admission were compared with six sequential organ failure assessment (SOFA) components (PaO 2 /FIO 2 [PF], platelets (PLT), bilirubin, cardiovascular, Glasgow Coma Scale score, and creatinine). The confidence interval (CI) was obtained by performing 10,000 repeated measurements via random sampling of the test dataset. All results were explained and interpreted using Shapley's additive explanations (SHAP)., Results: Of the 5,112 participants, CatBoost exhibited the highest area under the curve (AUC) of 0.800 (95% CI, 0.756-0.840) using clinical variables. Using the SOFA components for the same patient, XGBoost exhibited the highest AUC of 0.678 (95% CI, 0.626-0.730). As interpreted by SHAP, albumin, lactate, blood urea nitrogen, and international normalization ratio were determined to significantly affect the results. Additionally, PF and PLTs in the SOFA component significantly influenced the prediction results., Conclusion: Newly established ML-based models achieved good prediction of mortality in patients with sepsis. Using several clinical variables acquired at the baseline can provide more accurate results for early predictions than using SOFA components. Additionally, the impact of each variable was identified., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023., Methods: A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1-adjusted odds ratio from multivariable logistic regression., Results: In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, -8, 49%)., Conclusion: The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: Shift work, including night shift work, during pregnancy has been associated with adverse birth outcomes such as small for gestational age (SGA) infants and preterm births. This study, conducted in South Korea using the Korean CHildren's ENvironmental health Study (Ko-CHENS) cohort, aimed to investigate the association between shift work and night shift status during pregnancy and adverse birth outcomes., Methods: The Korean Ko-CHENS is a nationwide prospective birth cohort study of children's environmental diseases, conducted by the Ministry of Environment and the National Institute of Environmental Research. This study included pregnant women recruited from 2015 to 2020 for Ko-CHENS Core Cohorts, and 4,944 out of a total of 5,213 pregnant women were selected as final subjects. A logistic regression model was used to identify the risk factors affecting SGA births, preterm births, and low-birth-weight infants, and the odds ratio (OR) was adjusted. This was confirmed by calculating ORs. Maternal age, infant sex, maternal educational status, body mass index, smoking status, alcohol consumption status, parity, gestational diabetes mellitus, preeclampsia, and abortion history were used as adjusted variables., Results: No statistically significant differences were observed in the birth outcomes or maternal working patterns. There were no significant differences in the adjusted odds ratios (aORs) of SGA and preterm births between the non-worker, day worker, and shift worker. However, there was a significant difference in the aORs of SGA between non-workers and night shift workers. (aORs [95% confidence interval], 2.643 [1.193-5.859])., Conclusion: Working during pregnancy did not increase the risk of SGA or preterm birth, and night shift work did not increase the risk of preterm birth. However, night-shift work increases the risk of SGA., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Social isolation and control owing to coronavirus disease 2019 (COVID-19) are easing; however, concerns regarding new infectious diseases have not disappeared. Given epidemic experiences such as severe acute respiratory syndrome (SARS), the influenza pandemic, Middle East respiratory syndrome (MERS), and COVID-19, it is necessary to prepare for the outbreak of new infectious diseases and situations in which large-scale vaccinations are required. Although the development of vaccines against COVID-19 has contributed greatly to overcoming the pandemic, concerning vaccine side effects from the general public, including medical personnel, and decreased confidence in vaccine efficacy and side effects, present many challenges in promoting and educating vaccinations for new infectious diseases in the future. In addition to plans to develop vaccines for the outbreak of new infectious diseases, education and promotion plans are necessary to administer the latest developments of vaccines to the general public. Moreover, efforts are needed to secure the necessity, legitimacy, and evidence for rapid vaccination on a large scale at the national level. It is also necessary to carefully prepare scientific bases and explanatory statements so that the general public can easily understand them. This study aimed to establish vaccine strategies and vaccination education plans for new infectious diseases that may occur in the future. Many ways to promote vaccination to the general public and healthcare workers should be prepared to ensure that the latest vaccines against new infectious diseases are administered safely. Thus, education and promotion of vaccine efficacy and safety based on specific data from clinical studies are necessary., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2023 The Korean Academy of Medical Sciences.)

Background: Targeted risk population has been highly vaccinated against pneumococcal diseases in South Korea. Despite this, the pneumococcal serotype distribution is evolving, which impedes efficient roll-out of vaccines., Methods: This prospective cohort study included patients aged ≥ 19 years with community-acquired pneumonia (CAP) from five university hospitals in South Korea between September 2018 and July 2021. The outcomes of interest were the demographic and clinical characteristics of patients with CAP, pneumococcal serotype distribution, and risk factors of 30-day mortality in patients with pneumococcal CAP (pCAP). Considering the high seroprevalence, we analyzed the clinical characteristics of serotype 3 pCAP., Results: A total of 5,009 patients hospitalized with CAP was included (mean age ± standard deviation, 70.3 ± 16.0 years; 3,159 [63.1%] men). Streptococcus pneumoniae was the leading causative agent of CAP (11.8% overall, 17.7% in individuals aged < 65 years with chronic medical conditions). Among the 280 serotyped Streptococcus pneumococcus , serotype 3 was the most common (10.0%), followed by serotypes 19A (8.9%), 34 (8.9%), and 35B (8.9%). Non-vaccine serotypes (serotype 35B [13.9%] and 34 [12.0%]) were the most prevalent in 108 individuals vaccinated with 23-valent pneumococcal polysaccharide vaccine (PPSV23). Serotype 3 was prevalent, irrespective of PPSV23 vaccination status, and more common in individuals with chronic lung disease ( P = 0.008). Advanced age (adjusted odds ratio [aOR], 1.040; 95% confidence interval [CI], 1.011-1.071), long-term care facility residence (aOR, 2.161; 95% CI, 1.071-4.357), and bacteremia (aOR, 4.193; 95% CI, 1.604-10.962) were independent risk factors for 30-day mortality in patients with pCAP. PPSV23 vaccination reduced the risk of mortality (aOR, 0.507; 95% CI, 0.267-0.961)., Conclusion: Serotype 3 and 19A were still the most common serotypes of pCAP in South Korea despite the national immunization program of 13-valent pneumococcal conjugated vaccine in children and PPSV23 in old adults. PPSV23 vaccination might reduce the risk of mortality in patients with pCAP., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2023 The Korean Academy of Medical Sciences.)

Background: Respiratory pathogen infections and air pollution are main causes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Air pollution has a direct effect on the airway epithelial barrier and the immune system, which can have an influence on infection. However, studies on the relationship between respiratory infections and air pollutants in severe AECOPD are limited. Thus, the objective of this study was to investigate the correlation between air pollution and respiratory pathogen in severe AECOPD., Methods: This multicenter observational study was conducted by reviewing electronic medical records of patients with AECOPD at 28 hospitals in South Korea. Patients were divided into four groups according to the comprehensive air-quality index (CAI) used in Korea. Identification rates of bacteria and viruses of each group were analyzed., Results: Viral pathogens were identified in 270 (36.7%) of 735 patients. Viral identification rate was different ( P = 0.012) according to air pollution. Specifically, the virus detection rate was 55.9% in the group of CAI 'D' with the highest air pollution. It was 24.4% in the group of CAI 'A' with the lowest air pollution. This pattern was clearly seen for influenza virus A ( P = 0.042). When further analysis was performed with particulate matter (PM), the higher/lower the PM level, the higher/lower the virus detection rate. However, no significant difference was found in the analysis related to bacteria., Conclusion: Air pollution may make COPD patients more susceptible to respiratory viral infections, especially influenza virus A. Thus, on days with poor air quality, COPD patients need to be more careful about respiratory infections., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2023 The Korean Academy of Medical Sciences.)

Since its first emergence in late 2019, severe acute respiratory syndrome coronavirus-2 has claimed more than 6.5 million lives worldwide and continues to infect hundreds of thousands of people daily. To combat this once-in-a-century disaster, several vaccines have been developed at unprecedented speeds. Novel vaccine platforms (messenger ribonucleic acid vaccines and adenoviral vector vaccines) have played a major role in the current pandemic. In Korea, six vaccines, including a domestically developed recombinant vaccine, have been approved. As in other countries, vaccines have been proven to be safe and highly effective in Korea. However, rare serious adverse events and breakthrough infections have undermined public trust in the vaccines, even while the benefits of vaccination far outweigh the risks. The rise of the omicron variant and the subsequent increase in excess mortality demonstrated that while vaccines are a key component of the pandemic response, it alone can fail without non-pharmaceutical interventions like masking and social distancing. The pandemic of coronavirus disease has revealed both the strengths and weaknesses of our healthcare system and pandemic preparedness. When the next pandemic arrives, improved risk communication and vaccine development should be prioritized. To enable timely vaccine development, it is essential to make strategic and sufficient investments in vaccine research and development., Competing Interests: All authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

As most individuals acquire immunity to severe acute respiratory syndrome coronavirus 2, South Korea declared a return to normalcy a few months ago. However, epidemic waves continue because of endlessly emerging variants and waning immunity. Health authorities are focusing on those at high risk of severe coronavirus disease 2019 to minimize damage to public health and the economy. In this regard, we investigated the vaccination rates in patients with various chronic medical conditions by examining the national health insurance claims data and the national immunization registry. We found that patients with chronic medical conditions, especially those of higher severity, such as malignancy, had vaccination rates approximately 10-20% lower than those of the general population. Public health authorities and healthcare providers should try to vaccinate these patients to avoid preventable morbidity and mortality., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to have high infectivity and is more likely to evade vaccine immunity. However, booster vaccination is expected to strengthen cross-reactive immunity, thereby increasing the vaccine effectiveness (VE). This study aimed to evaluate the relative VE of the 3-dose (booster) vaccination compared with the 2-dose primary series vaccination in healthcare workers during omicron variant-dominant periods. During the omicron-dominant period from February 1, 2022 to February 28, 2022, a 1:1 matched case-control study was conducted. Healthcare workers with positive SARS-CoV-2 test results were classified as positive cases, whereas those with negative results served as controls. Compared with the 2-dose primary series vaccination, booster vaccination with mRNA vaccine showed moderate VE (53.1%). However, in multivariate analysis including the time elapsed after vaccination, the significant VE disappeared, reflecting the impact of recent vaccination rather than the third dose itself., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Background: As the coronavirus disease 2019 (COVID-19) pandemic continues, there are concerns regarding waning immunity and the emergence of viral variants. The immunogenicity of Ad26.COV2.S against wild-type (WT) and variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated., Method: This prospective cohort study was conducted between June 2021 and January 2022 at two university hospitals in South Korea. Healthy adults who were scheduled to be vaccinated with Ad26.COV2.S were enrolled in this study. The main outcomes included anti-spike (S) IgG antibody and neutralizing antibody responses, S-specific T-cell responses (interferon-γ enzyme-linked immunospot assay), solicited adverse events (AEs), and serious AEs., Results: Fifty participants aged ≥ 19 years were included in the study. Geometric mean titers (GMTs) of anti-S IgG were 0.4 U/mL at baseline, 5.2 ± 3.0 U/mL at 3-4 weeks, 55.7 ± 2.4 U/mL at 5-8 weeks, and 81.3 ± 2.5 U/mL at 10-12 weeks after vaccination. GMTs of 50% neutralizing dilution (ND50) against WT SARS-CoV-2 were 164.6 ± 4.6 at 3-4 weeks, 313.9 ± 3.6 at 5-8 weeks, and 124.4 ± 2.6 at 10-12 weeks after vaccination. As for the S-specific T-cell responses, the median number of spot-forming units/10 6 peripheral blood mononuclear cell was 25.0 (5.0-29.2) at baseline, 60.0 (23.3-178.3) at 5-8 weeks, and 35.0 (13.3-71.7) at 10-12 weeks after vaccination. Compared to WT SARS-CoV-2, ND50 against Delta and Omicron variants was attenuated by 3.6-fold and 8.2-fold, respectively. The most frequent AE was injection site pain (82%), followed by myalgia (80%), fatigue (70%), and fever (50%). Most AEs were grade 1-2, and resolved within two days., Conclusion: Single-dose Ad26.COV2.S was safe and immunogenic. NAb titer and S-specific T-cell immunity peak at 5-8 weeks and rather decrease at 10-12 weeks after vaccination. Cross-reactive neutralizing activity against the Omicron variant was negligible., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Background: A cervical transforaminal epidural (TFE) steroid injection is a useful treatment option for cervical radicular pain, but it carries a small risk of catastrophic complications. Several studies have reported that cervical facet joint (FJ) steroid injection can reduce cervical radicular pain through an indirect epidural spread. The aim of this retrospective comparative study was to evaluate the pain scores and functional disability in subjects receiving cervical FJ or TFE steroid injection for the treatment of cervical radicular pain due to foraminal stenosis (FS)., Methods: We selected 278 patients 18 years of age and older who underwent cervical FJ (n = 130) or TFE (n= 148) steroid injection for cervical radicular pain. The primary outcomes included pain scores and functional disability during hospital visits one, three, and six months after the initial injection. Secondary outcomes were the proportion of responders and Medication Quantification Scale (MQS) scores. Adverse events and variables correlating with effectiveness one month after the initial injection were also evaluated., Results: The Numeric Rating Scale and Neck Disability Index scores showed a significant improvement one, three, and six months after the initial injection in both groups, with no significant differences between the groups. No significant differences were observed in the success rates of the procedure one, three, and six months after the initial injection for either group. There were no significant differences in MQS between the groups during the follow-up period. Univariate and multivariate logistic regression analyses revealed that the injection method, age, sex, number of injections, FS severity, MQS, pain duration, and the presence of cervical disc herniation were not independent predictors of treatment success., Conclusion: The efficacy of FJ steroid injection may not be inferior to that of TFE steroid injection in patients with cervical radicular pain due to FS., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Background: Lumbar transforaminal epidural block (TFEB) is an effective treatment modality for radicular pain due to lumbar disc herniation (LDH). The addition of steroids is more effective than local anesthetic alone in TFEBs for patients with LDH. Moreover, the efficacy of TFEBs has been reported to be positively correlated with the volume of injectate. We hypothesized that high-volume TFEBs without steroids effectively alleviate axial back and radicular pain associated with LDH. This study compared the efficacy of high-volume TFEBs with vs. without steroids for the management of the axial and radicular pain caused by LDH., Methods: A total of 54 patients were randomly assigned to either group L or group D. Patients in group L received 8-mL injections of 0.33% lidocaine only. Patients in group D received 8-mL injections of 0.33% lidocaine with 5 mg of dexamethasone. The primary outcomes were pain intensity at baseline and 4 weeks after the procedure. The secondary outcomes included the change of functional disability between baseline and 4 weeks after the procedure, pain scores during injection, and adverse effects., Results: Both groups showed a significant reduction in axial and radicular pain and improvement in the functional status at the outpatient visit 4 weeks after TFEB. However, there were no significant differences between the groups in terms of changes in back pain (10.00 [20.00] vs. 10.00 [22.50]; P = 0.896) or radicular pain (5.00 [20.00] vs. 10.00 [12.50]; P = 0.871)., Conclusion: High-volume TFEBs with and without steroid administration yielded similar significant pain reductions and functional improvements among LDH patients 4 weeks after the procedure., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Background: Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD. Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding., Methods: To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD., Results: Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219, P = 0.015)., Conclusion: Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Since February 26, 2021, when vaccination against coronavirus disease 2019 (COVID-19) began in South Korea, patients who visited the Korea University Guro Hospital with suspected adverse events after COVID-19 vaccination were monitored actively with interest. We encountered five unusual cases of polyarthralgia and myalgia syndrome in patients who received the ChAdOx1 nCOV-19 (AstraZeneca) vaccine. The patients (median age 67 years) were not previously diagnosed with arthropathy and rheumatologic diseases. They developed fever, myalgia, joint pain, and swelling three to seven days after vaccination. The symptoms persisted for up to 47 days despite antipyretic treatment. Arthralgia occurred in multiple joints, including small and large joints. A whole-body Technetium-99m methylene diphosphonate bone scan revealed unusual uptakes in the affected joints. Non-steroidal anti-inflammatory drugs with or without prednisolone relieved the symptoms of all patients. Further monitoring is required to clarify the long-term prognosis of this syndrome., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Hospital-based surveillance for adverse events was conducted on healthcare workers after they received the first dose of coronavirus disease 2019 (COVID-19) vaccine. Among the two new platform vaccines (messenger RNA- and adenoviral vector-based vaccines), the rates of systemic adverse events were significantly higher among adenovirus-vectored vaccine recipients. Fatigue (87.6% vs. 53.8%), myalgia (80.8% vs. 50.0%), headache (72.0% vs. 28.8%), and fever (≥ 38.0°C, 38.7% vs. 0%) were the most common adverse events among adenovirus-vectored vaccine recipients, but most symptoms resolved within 2 days. Both types of COVID-19 vaccines were generally safe, and serious adverse events rarely occurred., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Background: In Korea, there were issues regarding the use of immunoassays for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies to detect infection. So, we compared antibody results of eight kinds of commercial immunoassays using clinical remnant specimens., Methods: We compared the results of several immunoassay kits tested on 40 serum samples from 15 confirmed patients and 86 remnant serum samples from clinical laboratory. Eight kinds of IVD kits-four enzyme-linked immunosorbent assay, two lateral flow rapid immunochromatographic assays, and two chemiluminescent immunoassays with one RUO kit were tested., Results: Among 40 serum samples from 15 coronavirus disease 2019 (COVID-19) patients, 35 yielded at least one positive result for detecting antibodies in the combined assessment. There were inconsistent results in 12 (28%) samples by single immunoassay. Forty samples collected in 2019 before the first COVID-19 Korean case showed negative results except for one equivocal result., Conclusion: The discrepant results obtained with different immunoassay kits in this study show that serological assessment of SARS-CoV-2 by a single immunoassay requires caution not only in detecting infection but also in assessing immunologic status., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Community-based health management policies are needed considering societal aging. We aimed to develop a transitional care model (TCM) program for patients with pneumonia, asthma, and chronic obstructive pulmonary disease. First, we conducted in-depth interviews with patients who were hospitalized, released, and readmitted for those three conditions to identify issues with the current hospitalization/discharge system and post-discharge processes. Next, we developed a new TCM program suited to the realities of the current medical environment. Interviews revealed problems including inadequate awareness of disease and health management; insufficient information exchange between patients, caregivers, and primary medical institutions; and absence/low usage of community-based care services. The investigation applying the new TCM program to patients and following up on readmission rates and life satisfaction after discharge is ongoing. Reviewing these results and conducting further studies in the future will allow improvements to the model., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Serosurveillance studies reveal the actual disease burden and herd immunity level in the population. In Seoul, Korea, a cross-sectional investigation showed 0.07% anti-severe acute respiratory syndrome coronavirus-2 antibody seropositivity among 1,500 outpatients of the university hospitals. Low seroprevalence reflects well-implemented social distancing. Serosurveillance should be repeated as the pandemic progresses., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Competing Interests: The authors have no potential conflicts of interest to disclose.

Background: Patients with coronavirus disease 2019 (COVID-19) can unknowingly spread the virus to several people during the early subclinical period., Methods: We evaluated the viral dynamics in various body fluid specimens, such as nasopharyngeal swab, oropharyngeal swab, saliva, sputum, and urine specimens, of two patients with COVID-19 from hospital day 1 to 9. Additional samples of the saliva were taken at 1 hour, 2 hours, and 4 hours after using a chlorhexidine mouthwash. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load was determined by real-time reverse transcriptase polymerase chain reaction (rRT-PCR)., Results: SARS-CoV-2 was detected from all the five specimens of both patients by rRT-PCR. The viral load was the highest in the nasopharynx (patient 1 = 8.41 log 10 copies/mL; patient 2 = 7.49 log 10 copies/mL), but it was also remarkably high in the saliva (patient 1 = 6.63 log 10 copies/mL; patient 2 = 7.10 log 10 copies/mL). SARS-CoV-2 was detected up to hospital day 6 (illness day 9 for patient 2) from the saliva of both patients. The viral load in the saliva decreased transiently for 2 hours after using the chlorhexidine mouthwash., Conclusion: SARS-CoV-2 viral load was consistently high in the saliva; it was relatively higher than that in the oropharynx during the early stage of COVID-19. Chlorhexidine mouthwash was effective in reducing the SARS-CoV-2 viral load in the saliva for a short-term period., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Social distancing has been adopted as one of basic protective measures against coronavirus disease 2019 (COVID-19). During 2019-2020 season, influenza epidemic period was exceptionally short and epidemic peak was low in comparison with previous seasons in Korea. Influenza epidemic pattern was bimodal in 2016-2017 and 2018-2019 seasons, however, influenza viruses have rarely been circulating in spring, 2020 in Korea. Although multiple factors could affect the size of influenza epidemic, extensive application of nonpharmaceutical interventions including mask wearing and social distancing in response to COVID-19 seems to be a major factor of reduced influenza epidemic. Social distancing measures with high feasibility and high acceptability should be implemented even if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are developed in the future. Establishment of guideline for workplace social distancing is needed and it would contribute to reduce disease burden of influenza, especially in vaccine mismatch year., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Background: Pulmonary functions are interpreted using predicted values from reference equations that vary with ethnicity, gender, age, height, and weight. The universally used Choi's reference equations are not validated for Korean populations, and the purpose of this study was to validate them and develop new reference equations., Methods: Subjects with normal spirometry and chest radiographs, no co-morbidities, and non-smokers, from the Korean National Health and National Examination Survey (KNHANES)-VI were enrolled (n = 117). Intraclass correlation coefficient (ICC) was assessed for reliability of reference equations. New reference equations were developed using linear regression analysis. Differences between observed and predicted values were assessed to compare the reference equations from Choi's, Global Lung Function Initiative 2012, KNHANES-IV, and newly developed equations., Results: The ICC of Choi's reference equations was 0.854 (P < 0.001). The new reference equations for men were: forced vital capacity (FVC) (L) = - 4.38775 - 0.01184 × age + 0.05547 × height, forced expiratory volume - 1 second (FEV₁) (L) = - 2.40147 - 0.02134 × age + 0.04103 × height; and for women: FVC (L) = - 3.09063 + 0.003904 × age + 0.038694 × height; FEV₁ (L) = - 1.32933 - 0.00872 × age + 0.02762 × height. The differences between the predicted and observed means were largest in Choi's equations, but lowest in the new equations with highest goodness of fit., Conclusion: Because Choi's reference equations presented larger differences from the observed values, despite reliability, and the new reference equations showed better goodness of fit, we suggest the latter for Korean populations., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: Peripheral arterial disease (PAD) is known as the greatest risk factor affecting the amputation of diabetic foot. Thus, it is crucial to understand the epidemiology of PAD associated with diabetic foot and the relationship between PTA and amputation in predicting prognosis. However, no such multi-year data are available in Korea. Thus, the purpose of this study was to investigate trends of amputation involving diabetic foot based on vascular interventions for PAD in Korea., Methods: This study was conducted using six-year data obtained from Health Insurance Review and Assessment Service from January 1, 2011 to December 31, 2016. Our study included data pertaining to diabetic foot, PAD, and vascular intervention codes (percutaneous transluminal angioplasty [PTA, M6597], percutaneous intravascular installation of stent-graft [PIISG, M6605], and percutaneous intravascular atherectomy [PIA, M6620]). We analyzed the number of vascular interventions and minor and major amputations each year. The relationship between annual amputation and vascular intervention was analyzed using χ² test., Results: The overall number of vascular interventions increased from 253 (PTA, 111; PIISG, 140; and PIA, 2) in 2011 to 1,230 (PTA, 745; PIISG, 470; and PIA, 15) in 2016. During the same period, the number of minor amputations increased from 2,534 to 3,319 while major amputations decreased from 980 to 956. The proportion of minor amputations among patients who underwent vascular intervention was significantly increased from 19.34% in 2011 to 21.45% in 2016 while the proportion of major amputations among these patients was significantly reduced from 9.88% to 4.27%. In addition, the association between vascular intervention and amputation increased from 0.56 (spearman correlation coefficient) in 2011 to 0.62 in 2016., Conclusion: In diabetic foot patients, increase in vascular intervention resulted in a change in amputation pattern, showing statistically significant correlation., Competing Interests: The authors have no potential conflict of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: Patients who survive an acute phase of stroke are at risk of falls and fractures afterwards. However, it is largely unknown how frequent fractures occur in the Asian stroke population., Methods: Patients with acute (< 7 days) ischemic stroke who were hospitalized between January 2011 and November 2013 were identified from a prospective multicenter stroke registry in Korea, and were linked to the National Health Insurance Service claim database. The incidences of fractures were investigated during the first 4 years after index stroke. The cumulative incidence functions (CIFs) were estimated by the Gray's test for competing risk data. Fine and Gray model for competing risk data was applied for exploring risk factors of post-stroke fractures., Results: Among a total of 11,522 patients, 1,616 fracture events were identified: 712 spine fractures, 397 hip fractures and 714 other fractures. The CIFs of any fractures were 2.63% at 6 months, 4.43% at 1 year, 8.09% at 2 years and 13.00% at 4 years. Those of spine/hip fractures were 1.11%/0.61%, 1.88%/1.03%, 3.28%/1.86% and 5.79%/3.15%, respectively. Age by a 10-year increment (hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.17-1.30), women (HR, 1.74; 95% CI, 1.54-1.97), previous fracture (HR, 1.72; 95% CI, 1.54-1.92) and osteoporosis (HR, 1.44; 95% CI, 1.27-1.63) were independent risk factors of post-stroke fracture., Conclusion: The CIFs of fractures are about 8% at 2 years and 13% at 4 years after acute ischemic stroke in Korea. Older age, women, pre-stroke fracture and osteoporosis raised the risk of post-stroke fractures., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: Little is known about epigenetic silencing of genes by promoter hypermethylation in renal cell carcinoma (RCC). The aim of this study was to identify prognostic methylation markers in surgically treated clear cell RCC (ccRCC)., Methods: Methylation patterns were assayed using the Infinium HumanMethylation450 BeadChip array on pairs of ccRCC and normal tissue from 12 patients. Using quantitative PSQ analysis, tumor-specific hypermethylated genes were validated in 25 independent cohorts and their clinical relevance was also verified in 152 independent cohorts., Results: Using genome-wide methylation array, Zinc finger protein 278 ( ZNF278 ), Family with sequence similarity 155 member A ( FAM155A ) and Dipeptidyl peptidase 6 ( DPP6 ) were selected for tumor-specific hypermethylated genes in primary ccRCC. The promoter methylation of these genes occurred more frequently in ccRCC than normal kidney in independent validation cohort. The hypermethylation of three genes were associated with advanced tumor stage and high grade tumor in ccRCC. During median follow-up of 39.2 (interquartile range, 15.4-79.1) months, 22 (14.5%) patients experienced distant metastasis. Multivariate analysis identified the methylation status of these three genes, either alone, or in a combined risk score as an independent predictor of distant metastasis., Conclusion: The promoter methylation of ZNF278 , FAM155A and DPP6 genes are associated with aggressive tumor phenotype and early development of distant metastasis in patients with surgically treated ccRCC. These potential methylation markers, either alone, or in combination, could provide novel targets for development of individualized therapeutic and prevention regimens., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: The association between restless legs syndrome (RLS) and hypertension remains controversial. We investigated the relationship between RLS and hypertension in a nationwide sample of the Korean adult population., Methods: This was a cross-sectional questionnaire-based study including 2,740 adults aged 19 years or more. Subjects who met the four essential International RLS Study Group criteria and reported symptoms occurring at least once a week were defined as the RLS group. The presence of hypertension was defined as a self-reported history of physician-diagnosed hypertension. We conducted multiple logistic regression analysis to determine the independent association between RLS symptoms and self-reported hypertension after adjusting for potential confounding factors., Results: Among the 2,740 subjects, 68 (2.5%; 95% confidence interval [CI], 1.9%-3.1%) were found to have RLS with a symptom frequency of at least once a week. The prevalence of self-reported hypertension was 30.9% (95% CI, 20.5%-42.0%) in the RLS group, which was significantly higher than that in controls (12.4%; 95% CI, 11.2%-13.6%; P < 0.001). Multiple logistic regression analysis showed that the adjusted odds ratio for self-reported hypertension in the RLS group was 2.10 (95% CI, 1.12-3.93) compared to controls. In addition to RLS symptoms, old age, being overweight, low education level, diabetes mellitus, and short sleep duration were significantly associated with self-reported hypertension., Conclusion: RLS symptoms occurring at least once a week is independently associated with a higher prevalence of self-reported hypertension in the adult Korean population. Further research will confirm the clinical implication of the present results and the causal relationship between RLS and hypertension., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2019 The Korean Academy of Medical Sciences.)

Background: Cell division cycle 6 (CDC6) is an essential regulator of DNA replication and plays important roles in the activation and maintenance of the checkpoint mechanisms in the cell cycle. CDC6 has been associated with oncogenic activities in human cancers; however, the clinical significance of CDC6 in prostate cancer (PCa) remains unclear. Therefore, we investigated whether the CDC6 mRNA expression level is a diagnostic and prognostic marker in PCa., Methods: The study subjects included 121 PCa patients and 66 age-matched benign prostatic hyperplasia (BPH) patients. CDC6 expression was evaluated using real-time polymerase chain reaction and immunohistochemical (IH) staining, and then compared according to the clinicopathological characteristics of PCa., Results: CDC6 mRNA expression was significantly higher in PCa tissues than in BPH control tissues ( P = 0.005). In addition, CDC6 expression was significantly higher in patients with elevated prostate-specific antigen (PSA) levels (> 20 ng/mL), a high Gleason score, and advanced stage than in those with low PSA levels, a low Gleason score, and earlier stage, respectively. Multivariate logistic regression analysis showed that high expression of CDC6 was significantly associated with advanced stage (≥ T3b) (odds ratio [OR], 3.005; confidence interval [CI], 1.212-7.450; P = 0.018) and metastasis (OR, 4.192; CI, 1.079-16.286; P = 0.038). Intense IH staining for CDC6 was significantly associated with a high Gleason score and advanced tumor stage including lymph node metastasis stage (linear-by-linear association, P = 0.044 and P = 0.003, respectively)., Conclusion: CDC6 expression is associated with aggressive clinicopathological characteristics in PCa. CDC6 may be a potential diagnostic and prognostic marker in PCa patients., Competing Interests: Disclosure: The authors have no potential conflict of interest to disclose.

Background: The safety and clinical effectiveness data of peramivir in the real clinical field are limited. A prospective observational study was conducted based on the post-marketing surveillance data to evaluate the post-marketing safety and effectiveness of peramivir in Korean adults with seasonal influenza., Methods: Among adults aged 20 years or older who were diagnosed with influenza A or B, patients who started peramivir within 48 hours from the initial symptoms of influenza were enrolled. All adverse events (AEs) that occurred within 7 days after administration of peramivir were checked. For the evaluation of effectiveness, changes in the severity of influenza symptoms and daily living performance were examined before and 7 days after the administration of peramivir. The date on which influenza related symptoms disappeared was checked., Results: A total of 3,024 patients were enrolled for safety evaluation and 2,939 patients were for effectiveness evaluation. In the safety evaluation, 42 AEs were observed in 35 (1.16%) patients. The most common AE was fever. AEs were mostly rated as mild in severity. Serious AEs were observed in 10 patients and two of them died. However, both deaths were considered to be less relevant to peramivir. In the effectiveness evaluation, the severity of influenza symptoms decreased by 10.68 ± 4.01 points and daily living performance was improved 5.59 ± 2.16 points. Influenza related symptoms disappeared on average 3.02 ± 2.39 days after peramivir administration., Conclusion: Peramivir showed a tolerable safety profile and acceptable effectiveness in Korean adult patients with seasonal influenza., Competing Interests: Disclosure: The sponsor participated in the post-marketing study design, execution, and the data collections. Although the sponsor reviewed the draft, the opinions expressed by the sponsor may not necessarily be reflected. The results of this study were presented as a poster at the 5th ISIRV-AVG conference.

Background: Lung cancer is the most common cause of cancer-related mortality worldwide. We previously reported the identification of a new genetic marker, cellular retinoic acid binding protein 2 (CRABP2), in lung cancer tissues. The aim of this study was to assess plasma levels of CRABP2 from patients with non-small cell lung cancer (NSCLC)., Methods: Blood samples that were collected from 122 patients with NSCLC between September 2009 and September 2013 were selected for the analysis, along with samples from age- (± 5 years), sex-, and cigarette smoking history (± 10 pack-years [PY])-matched controls from the Korea Biobank Network. The control specimens were from patients who were without malignancies or pulmonary diseases. We measured plasma levels of CRABP2 using commercially available enzyme-linked immunosorbent assay kits., Results: The mean age of the NSCLC patients was 71.8 ± 8.9 years, and the median cigarette smoking history was 32 PY (range, 0-150 PY). Plasma CRABP2 levels were significantly higher in patients with NSCLC than in the matched controls (37.63 ± 28.71 ng/mL vs. 24.09 ± 21.09 ng/mL, P < 0.001). Higher plasma CRABP2 levels were also correlated with lower survival rates in NSCLC patients ( P = 0.014)., Conclusion: Plasma CRABP2 levels might be a novel diagnostic and prognostic marker in NSCLC., Competing Interests: Disclosure: The authors have no potential conflicts of interest to disclose.

Background: Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease. To date, a large number of clinical studies have been conducted to investigate the association between genetic variations and COPD. However, little is known regarding the genetic susceptibility of Koreans to this disease. MER receptor tyrosine kinase (MERTK) plays important roles in the inhibition of inflammation and in the clearance of apoptotic cells. Here, we investigated the association between genetic variations in MERTK and the development of COPD in Koreans., Methods: We conducted genetic analysis of MERTK using genomic DNA samples from 87 patients with COPD and 88 healthy controls and compared the frequency of each variation or haplotype between the patient and control groups. Subsequently, the effect of each variation was evaluated using in vitro assays., Results: Ten variations were identified in this study, four of them for the first time. In addition, we found that the frequency of each variation or haplotype was comparable between the patient and control groups. However, we observed that the frequency for the wild-type haplotype was higher in the control group, compared to that in the group of patients with COPD, in the subgroup analysis of current smokers, although the difference was not statistically significant (P = 0.080). In in vitro assays, we observed that none of the variations affected the activity of the promoter or the expression of MERTK., Conclusion: Our findings indicate that the susceptibility to COPD is not related to the genetic variations or haplotypes of MERTK in Koreans., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2018 The Korean Academy of Medical Sciences.)

Since 2013, the Hospital-based Influenza Morbidity and Mortality (HIMM) surveillance system began a H7N9 influenza surveillance scheme for returning travelers in addition to pre-existing emergency room (ER)-based influenza-like illness (ILI) surveillance and severe acute respiratory infection (SARI) surveillance. Although limited to eastern China, avian A/H7N9 influenza virus is considered to have the highest pandemic potential among currently circulating influenza viruses. During the study period between October 1st, 2013 and April 30th, 2016, 11 cases presented with ILI within seven days of travel return. These patients visited China, Hong Kong, or neighboring Southeast Asian countries, but none of them visited a livestock market. Seasonal influenza virus (54.5%, 6 among 11) was the most common cause of ILI among returning travelers, and avian A/H7N9 influenza virus was not detected during the study period., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2018 The Korean Academy of Medical Sciences.)

Urolithiasis is common and is becoming more prevalent worldwide. This study assessed the chronological trends in clinical and urinary metabolic features over 20 years in Korean urolithiasis patients. We performed a retrospective analysis of 4,076 patients treated at our clinic from 1996 to 2015. Urinary metabolic data and stone analysis data were available for 1,421 and 723 patients (34.9% and 17.7%), respectively. Patients were categorized into 4 groups according to the date of initial diagnosis: group 1 (1996-2000, n = 897), group 2 (2001-2005, n = 1,018), group 3 (2006-2010, n = 1,043), and group 4 (2011-2015, n = 1,118). Incidental detection of uric acid renal stones has become more prevalent in the past 10 years, accompanied by an increase in body mass index and age at diagnosis. Similarly, the prevalence of diabetes mellitus and of hypertension increased from one group to the next throughout the study period. Levels of 24-hour urinary excretion of sodium, calcium, uric acid, and oxalate have decreased significantly over the study period. The incidence of urinary metabolic abnormalities also showed an identical tendency. The proportion of stones composed of uric acid increased over the study period. In conclusion, incidental detection of uric acid renal stones has become more prevalent in Korea in the past 20 years. Urinary excretion of lithogenic constituents and the incidence of urinary metabolic abnormalities have decreased significantly over this period., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2017 The Korean Academy of Medical Sciences.)

Currently, metabolic complications are the most common problem among human immunodeficiency virus (HIV)-infected patients, with a high incidence. However, there have been very few studies regarding metabolic abnormalities published in Asia, especially in Korea. This cross-sectional study was performed to investigate the prevalence of and risk factors for metabolic abnormalities in 1,096 HIV-infected patients of the Korea HIV/AIDS cohort study enrolled from 19 hospitals between 2006 and 2013. Data at entry to cohort were analyzed. As a result, the median age of the 1,096 enrolled subjects was 46 years, and most patients were men (92.8%). The metabolic profiles of the patients were as follows: median weight was 63.8 kg, median body mass index (BMI) was 22.2 kg/m², and 16.4% of the patients had a BMI over 25 kg/m². A total of 5.5% of the patients had abdominal obesity (waist/hip ratio ≥ 1 in men, ≥ 0.85 in women). Increased levels of fasting glucose, total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides were present in 10.4%, 6.0%, 5.5%, and 32.1% of the patients. Decreased high-density lipoprotein (HDL) cholesterol levels were observed in 44.2% of the patients. High systolic blood pressure was present in 14.3% of the patients. In multivariate analysis, high BMI and the use of protease inhibitors (PIs) were risk factors for dyslipidemia in HIV-infected patients. In conclusion, proper diagnosis and management should be offered for the prevalent metabolic complications of Korean HIV-infected patients. Further studies on risk factors for metabolic complications are needed., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2017 The Korean Academy of Medical Sciences.)

Two prospective, multi-centre, observational studies (GlaxoSmithKline [GSK] identifier No. 110938 and 112519) were performed over 2 influenza seasons (2007-2008 and 2008-2009) in the Republic of Korea (ROK) with the aim to evaluate the burden of laboratory-confirmed influenza (LCI) in patients ≥ 50 years of age seeking medical attention for acute respiratory illness (ARI). The median participant age was 58 years in the 2007-2008 season and 60 years in the 2008-2009 season. LCI was observed in 101/346 (29.2%) of ARI patients in the 2007-2008 season and in 166/443 (37.5%) of ARI patients in the 2008-2009 season. Compared to patients with non-influenza ARI, those with LCI had higher rates of decreased daily activities (60.4% vs. 32.9% in 2007-2008 and 46.4% vs. 25.8% in 2008-2009), work absenteeism (51.1% vs. 25.6% and 14.4% vs. 7.7%), and longer duration of illness. These results indicated that influenza is an important cause of ARI in adults aged 50 and older causing more severe illness than non-influenza related ARI., Competing Interests: All authors completed the disclosure declaration. Matias G, Ray R, Carneiro R, and Haguinet F are employed by the GlaxoSmithKline (GSK) Group of Companies. Ray R reports ownership of stock options and/or restricted shares. Kyaw M and Monegal JS report having been employed by the GSK Group of Companies at the time of the study. Kim WJ, Lee CK, Cheong HJ, Lee JS, and Kim M report no competing interests. Involvement of GSK employees did not compromise the scientific integrity of this work.

The aim of the present multi-institutional study was to assess the influence of the American Society of Anesthesiologists Physical Status (ASA-PS) classification on adjuvant chemotherapy eligibility and survival in a multi-institutional cohort of patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). We retrospectively reviewed data from 416 patients who underwent RNU for UTUC at four Korean institutions between 2001 and 2013. The ASA-PS classification was obtained from the anesthesia chart. Locally advanced UTUC was defined as ≥ pT3 and/or pN1 disease. The influence of ASA-PS score on survival was evaluated by Kaplan-Meier analyses and a multivariate Cox regression model. Patients with a higher ASA-PS class were less likely to be eligible for adjuvant chemotherapy in locally advanced UTUC (P = 0.016). Kaplan-Meier estimates showed that the high-risk ASA-PS group has a poorer overallsurvival (OS) and cancer-specific survival (CSS) compared to low risk ASA-PS groups in both the total and locally advanced UTUC cohorts. Based on multivariate Cox regression analysis, the high-risk ASA-PS category was an independent predictor for overall mortality (OM) (hazard ratio [HR], 1.919; 95% confidence interval [CI], 1.017-3.619; P = 0.044) and cancer-specific mortality (CSM) (HR, 2.120; 95% CI, 1.023-4.394; P = 0.043). In conclusion, high-risk ASA-PS score was independently associated with a lower survival rate in patients with UTUC after RNU. However, the influence of ASA-PS classification on survival was limited to locally advanced UTUC. The lower eligibility of patients in the high-risk ASA category for adjuvant chemotherapy may contribute to the lower survival rate in this group., Competing Interests: The authors have no potential conflicts of interest to disclose.

The prognostic significance of age in renal cell carcinoma (RCC) is a subject of debate. The aim of the present multi-institutional study was to evaluate the impact of age on clinicopathological features and survival in a large cohort of patients with RCC. A total of 5,178 patients who underwent surgery for RCC at eight institutions in Korea between 1999 and 2011 were categorized into three groups according to age at diagnosis as follows: young age (< 40 years, n = 541), middle-age (≥ 40 and < 60 years, n = 2,551), and old age (≥ 60 years, n = 2,096) groups. Clinicopathological variables and survival rates were compared between the three groups. Young patients had lower stage tumors with a low Fuhrman grade, a lower rate of lymphovascular invasion than patients in the other age groups. Regarding histologic type, the young age group had a lower percentage of clear cell histology and a greater incidence of Xp11.2 translocation RCC. Kaplan-Meier estimates showed that cancer-specific survival was significantly better in the young age group than in the other groups (log rank test, P = 0.008). However, age at diagnosis was not an independent predictor of survival in multivariate analysis. In conclusion, young age at diagnosis was associated with favorable pathologic features, although it was not an independent prognostic factor for survival in patients with surgically-treated RCC. Age itself should not be regarded as a crucial determinant for the treatment of RCC., Competing Interests: The authors have no potential conflicts of interest to disclose.

This study aimed to evaluate the efficacy, safety, and tolerability of 2-cycled neoadjuvant sunitinib therapy (NST) in patients with inoperable metastatic renal cell carcinoma (mRCC). Between 2009 and 2012, 14 patients with inoperable mRCC from 5 Korean academic centers were prospectively enrolled after collecting their clinicopathological data and completing health-related questionnaires. The best overall response (BOR), safety profile, and changes in quality of life during NST were assessed using the RECIST criteria (version 1.0), CTCAE criteria (version 4.0), and the Cancer Quality of Life Questionnaire (QLQ-C30). Among the 14 patients, 9 patients (64.3%) experienced partial response or stable disease state, and 5 patients (35.7%) did not complete treatment, with 1 case of disease progression (7.1%), 3 grade 3 adverse events (21.4%), and 1 voluntary withdrawal (7.1%). Four patients (28.6%) were successfully converted to an operable state and underwent surgery after NST. The BOR for the primary renal lesions was 22.2%, with a median 1.3-cm diameter reduction (range: 0-2.8 cm) from a baseline diameter of 10.3 cm (range: 6.6-15.8 cm). The other 18 measurable metastatic lesions exhibited a BOR of 55.6%. The QLQ-C30 questionnaire results revealed significant improvements in the quality of life domain, although we observed significant increases in the scores for fatigue, nausea and vomiting, and the financial effects of NST (P < 0.05). Two-cycle NST provided limited efficacy for resectability of inoperable mRCC, despite mild improvements in the BOR of the primary lesion and quality of life (Clinical Trial Registry 1041140-1)., Competing Interests: The corresponding author (Dr. Jinsoo Chung) has acted as a consultant for Pfizer. The other authors did not receive funding from Pfizer and have no conflicts of interests regarding this manuscript. In addition, Pfizer had no involvement in the collection, analysis, and interpretation of data for this manuscript, the writing of this manuscript, or the decision to submit it for publication. All the data collection and analysis for this study were performed based on an academic objectivity.

Pregnant women are prioritized to receive influenza vaccination. However, the maternal influenza vaccination rate has been low in Korea. To identify potential barriers for the vaccination of pregnant women against influenza, a survey using a questionnaire on the perceptions and attitudes about maternal influenza vaccination was applied to Korean obstetricians between May and August of 2014. A total of 473 respondents participated in the survey. Most respondents (94.8%, 442/466) recognized that influenza vaccination was required for pregnant women. In addition, 92.8% (410/442) respondents knew that the incidence of adverse events following influenza vaccination is not different between pregnant and non-pregnant women. However, 26.5% (124/468) obstetricians strongly recommended influenza vaccination to pregnant women. The concern about adverse events following influenza vaccination was considered as a major barrier for the promotion of maternal influenza vaccination by healthcare providers. Providing professional information and education about maternal influenza vaccination will enhance the perception of obstetricians about influenza vaccination to pregnant women and will be helpful to improve maternal influenza vaccination coverage in Korea.

The poisoning information database (PIDB) provides clinical toxicological information on commonly encountered toxic substances in Korea. The aim of this study was to estimate the coverage rate of the PIDB by comparing the database with the distribution of toxic substances that real poisoning patients presented to 20 emergency departments. Development of the PIDB started in 2007, and the number of toxic substances increased annually from 50 to 470 substances in 2014. We retrospectively reviewed the medical records of patients with toxic exposure who visited 20 emergency departments in Korea from January to December 2013. Identified toxic substances were classified as prescription drug, agricultural chemical, household product, animal or plant, herbal drug, or other. We calculated the coverage rate of the PIDB for both the number of poisoning cases and the kinds of toxic substances. A total of 10,887 cases of intoxication among 8,145 patients was collected. The 470 substances registered in the PIDB covered 89.3% of 8,891 identified cases related to poisoning, while the same substances only covered 45.3% of the 671 kinds of identified toxic substances. According to category, 211 prescription drugs, 58 agricultural chemicals, 28 household products, and 32 animals or plants were not covered by the PIDB. This study suggested that the PIDB covered a large proportion of real poisoning cases in Korea. However, the database should be continuously extended to provide information for even rare toxic substances.

Current guidelines recommend that coronary artery calcium (CAC) screening should only be used for intermediate risk groups (Framingham risk score [FRS] of 10%-20%). The CAC distributions and coronary artery disease (CAD) prevalence in various FRS strata were determined. The benefit to lower risk populations of CAC score-based screening was also assessed. In total, 1,854 participants (aged 40-79 years) without history of CAD, stroke, or diabetes were enrolled. CAC scores of > 0, ≥ 100, and ≥ 300 were present in 33.8%, 8.2%, and 2.9% of the participants, respectively. The CAC scores rose significantly as the FRS grew more severe (P < 0.01). The total CAD prevalence was 6.1%. The occult CAD prevalence in the FRS ≤ 5%, 6%-10%, 11%-20%, and > 20% strata were 3.4%, 6.7%, 9.0%, and 11.6% (P < 0.001). In multivariate logistic regression analysis adjusting, not only the intermediate and high risk groups but also the low risk (FRS 6%-10%) group had significantly increased odds ratio for occult CAD compared to the very low-risk (FRS ≤ 5%) group (1.89 [95% confidence interval, CI, 1.09-3.29] in FRS 6%-10%; 2.48 [95% CI, 1.47-4.20] in FRS 11%-20%; and 3.10 [95% CI, 1.75-5.47] in FRS > 20%; P < 0.05). In conclusion, the yield of screening for significant CAC and occult CAD is low in the very low risk population but it rises in low and intermediate risk populations.

Given the rapid growth of the population of cancer survivors, increased attention has been paid to their health problems. Although gastric cancer is one of the most common cancers, empirical evidence of survivorship care is limited. The objectives of this study were to describe the health care status of gastric cancer survivors and to report the experience of using the shared-care model during a one-year experience at the cancer survivorship clinic in Seoul National University Hospital. This is a descriptive, single-center study of 250 long-term gastric cancer survivors who were referred to the survivorship clinic. The status of their health behaviors, comorbid conditions, secondary cancer screenings, and survivorship care status were investigated through questionnaires and examining the medical records. Among the survivors, 7.2% were current smokers, 8.8% were at-risk drinkers, and 32.4% were physically inactive. Among the patients who did not know their bone density status, the majority were in the osteopenic (37.1%) or osteoporotic range (24.1%). Screening among the eligible population within the recommended time intervals were 76.3% for colorectal cancer, but only 13.6% for lung cancer. All of the survivors were provided with counseling and medical management at the survivorship clinic, as appropriate. In conclusion, Long-term gastric cancer survivors have various unmet needs. Shared-care through survivorship clinics can be an effective solution for providing comprehensive care to cancer survivors.

The potential use of urinary nucleic acids as diagnostic markers in prostate cancer (PCa) was evaluated. Ninety-five urine samples and 234 prostate tissue samples from patients with PCa and benign prostatic hyperplasia (BPH) were analyzed. Micro-array analysis was used to identify candidate genes, which were verified by the two-gene expression ratio and validated in tissue mRNA and urinary nucleic acid cohorts. Real-time quantitative polymerase chain reaction (qPCR) was used to measure urinary nucleic acid levels and tissue mRNA expression. The TSPAN13-to-S100A9 ratio was selected to determine the diagnostic value of urinary nucleic acids in PCa (P = 0.037) and shown to be significantly higher in PCa than in BPH in the mRNA and nucleic acid cohort analyses (P < 0.001 and P = 0.013, respectively). Receiver operating characteristic (ROC) analysis showed that the area under the ROC curve was 0.898 and 0.676 in tissue mRNA cohort and urinary nucleic acid cohort, respectively. The TSPAN13-to-S100A9 ratio showed a strong potential as a diagnostic marker for PCa. The present results suggest that the analysis of urine supernatant can be used as a simple diagnostic method for PCa that can be adapted to the clinical setting in the future.

The prognostic impact of body mass index (BMI) in patients with upper tract urothelial carcinoma (UTUC) is an ongoing debate. Our study aimed to investigate the prognostic role of BMI in patients treated with radical nephroureterectomy (RNU) for UTUC from a multi-institutional Korean collaboration. We retrospectively reviewed data from 440 patients who underwent RNU for UTUC at four institutions in Korea. To avoid biasing the survival estimates, patients who had previous or concomitant muscle-invasive bladder tumors were excluded. BMI was categorized into approximate quartiles with the lowest quartile assigned to the reference group. Kaplan-Meier and multivariate Cox regression analyses were performed to assess the influence of BMI on survival. The lower quartile BMI group showed significantly increased overall mortality (OM) and cancer specific mortality (CSM) compared to the 25%-50% quartiles and upper quartile BMI groups. Kaplan-Meier estimates showed similar results. Based on multivariate Cox regression analysis, preoperative BMI as a continuous variable was an independent predictor for OM and CSM. In conclusion, preoperative underweight patients with UTUC in Korea survive less after RNU. Preoperative BMI may provide additional prognostic information to establish risk factors.

Mps one binder (MOB) proteins are integral components of signaling pathways that control important cellular processes, such as mitotic exit, centrosome duplication, apoptosis, and cell proliferation. However, the biochemical and cellular functions of the human MOB (hMOB) protein family remain largely unknown. The present study investigated the association between hMOB3B expression and clinicopathological characteristics of prostate cancer (PCa).Study subjects included 137 PCa patients and 137 age-matched benign prostatic hyperplasia (BPH) patients. hMOB3B expression was estimated using real-time PCR and compared with clinicopathological parameters of PCa. hMOB3B mRNA expression was significantly lower in PCa tissues than in BPH control tissues (P<0.001). According to receiver operating characteristics curve analysis, the sensitivity of hMOB3B expression for PCa diagnosis was 84.7%, with a specificity of 86% (AUC=0.910; 95% CI=0.869-0.941; P<0.001). hMOB3B expression was significantly lower in patients with elevated prostate specific antigen (PSA) levels (≥10 ng/mL), a Gleason score≥8, and metastatic disease (any T, N+/M+) than in those with low PSA levels, a low Gleason score, and non-metastatic disease (each P<0.05). In conclusion, low levels of hMOB3B are closely associated with aggressive clinicopathologic features in patients with PCa. Our results suggest that hMOB3B may act as a tumor suppressor in human PCa.

The aim of this study was to evaluate the association of plasma fibroblast growth factor (FGF)-21 with angiographically significant coronary artery disease (CAD) in patients with type 2 diabetes mellitus. Serum FGF-21 was measured in 120 patients undergoing coronary angiography. Patients were divided into 4 groups based on the presence/absence of type 2 diabetes mellitus and of significant CAD. The atherosclerotic burden was obtained by two angiographic scores: Gensini score (GS) and Extent score (ES). FGF-21 levels were higher in type 2 diabetes mellitus than in non-diabetic patients (P = 0.014). FGF-21 levels were significantly correlated with GS (r = 0.358, P < 0.001) and ES (r = 0.324, P < 0.001) in univariate analysis with all patients. After adjusting for several confounding factors, both GS and ES were associated with FGF-21 in all patients (r = 0.271, P = 0.014; r = 0.217, P = 0.041, respectively). However, FGF-21 lost significant correlation with both GS and ES with type 2 diabetes mellitus in the final model. The patients with type 2 diabetes mellitus and CAD feature had elevated FGF-21 levels. Despite of a limited role in diabetic patients, FGF-21 levels are independently associated with angiographic severity and extent of CAD.