The COVID-19 Vaccine Safety Research Committee (CoVaSC) was established in November 2021 to address the growing need for independent, in-depth scientific evidence on adverse events (AEs) following coronavirus disease 2019 (COVID-19) vaccination. This initiative was requested by the Korea Disease Control and Prevention Agency and led by the National Academy of Medicine of Korea. In September 2022, the COVID-19 Vaccine Safety Research Center was established, strengthening CoVaSC’s initiatives. The center has conducted various studies on the safety of COVID-19 vaccines. During CoVaSC’s second research year, from September 29, 2022 to July 19, 2023, the center was restructured into 4 departments: Epidemiological Research, Clinical Research, Communication & Education, and International Cooperation & Policy Research. Its main activities include (1) managing CoVaSC and the COVID-19 Vaccine Safety Research Center, (2) surveying domestic and international trends in AE causality investigation, (3) assessing AEs following COVID-19 vaccination, (4) fostering international collaboration and policy research, and (5) organizing regular fora and training sessions for the public and clinicians. Causality assessments have been conducted for 27 diseases, and independent research has been conducted after organizing ad hoc committees comprising both epidemiologists and clinical experts on each AE of interest. The research process included protocol development, data analysis, interpretation of results, and causality assessment. These research outcomes have been shared transparently with the public and healthcare experts through various fora. The COVID-19 Vaccine Safety Research Center plans to continue strengthening and expanding its research activities to provide reliable, high-quality safety information to the public.

Objectives: Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. Methods: We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the correspondingsampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic ofKorea were estimated by applying the algorithms and weighted PPV and NPV to the 2018National Health Insurance Service claims data. Results: In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. Conclusion This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Objective: The abuse of prescription drugs and over-the-counter medicines has been a major issue addressed as a serious public health problem worldwide. This study explored factors contributing to substance abuse in Korea by examining the status of substance abuse among Korean adults and evaluating their knowledge, attitudes, and intentions toward substance abuse. Methods: Data were collected online from a sample of participants 19 years old or older from May 20 to June 1, 2020 (n=1,020). The survey consisted of questions on demographics, perceptions of drug risk, motives for drug use, and attitudes toward drug addiction treatment. Principal component and multiple logistic regression analyses were used to explore the factors contributing to the perception of drug abuse. Results: In the multivariate regression analysis, overconfidence in handling drug usage, acceptance of addictive substances, and affirmation of public support for drug abuse were associated with opioid abuse (Nagelkerke R2=0.486), and additionally affirmation of legal cannabis usage and motivation to use diet pills were associated with diet pill abuse (Nagelkerke R2=0.569). Conclusion The findings of this study suggest that the actual situation of substance abuse among Korean adults increases awareness of and attitudes toward drug use related to substance abuse.

Background/Aims: Colorectal adenomas are precancerous lesions that may lead to colorectal cancer. Recent studies have shown that colorectal adenomas are associated with atherosclerosis. The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) are noninvasive methods for evaluating atherosclerosis. This study examined the association between atherosclerosis and high-risk colorectal adenomas based on the CAVI and ABI. Methods: The data of patients aged ≥50 years who had a colonoscopy and CAVI and ABI measurements from August 2015 to December 2021 at the Kangwon National University Hospital were analyzed retrospectively. After the colonoscopy, subjects were divided into no, overall, and high-risk (size ≥1 cm, high-grade dysplasia or villous adenoma, three or more adenomas) adenoma groups based on the pathology findings. The data were subjected to univariate and multivariate logistic regression analyses. Results: Among the 1,164 subjects, adenomas and high-risk adenomas were found in 613 (52.6%) and 118 (10.1%) patients, respectively. The rate of positive ABI (<0.9) and positive CAVI (≥9.0) were significantly higher in the high-risk adenoma group (22.0% and 55.9%) than in the no adenoma (12.3% and 39.6%) and the overall adenoma group (15.7% and 44.0%) (p=0.008 and p=0.006, respectively). Multivariate analysis revealed a positive CAVI and smoking status to be significantly associated with high-risk adenoma with an odds ratio of 1.595 (95% confidence interval 1.055–2.410, p=0.027) and 1.579 (1.072–2.324, p=0.021), respectively. Conclusions In this study, a significant correlation between positive CAVI and high-risk adenomas was observed. Therefore, CAVI may be a significant predictor for high-risk colorectal adenoma.

The Korean Breast Cancer Society (KBCS) has collected nationwide registry data on clinicopathologic characteristics and treatment since 1996. This study aimed to analyze the clinical characteristics of breast cancer in Korea and assess changes in breast cancer statistics for 2021 using data from the KBCS registry and the Korean Central Cancer Registry. In 2021, 34,628 women were newly diagnosed with breast cancer. The median age of women diagnosed with breast cancer was 53.4 years, with the highest incidence occurring in the 40–49 age group. The most common molecular subtype was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative, accounting for 69.1% of cases, while HER2-positive subtypes comprised 19.3%. During the coronavirus disease 2019 pandemic, the national breast cancer screening rate declined. However, the incidence of early-stage breast cancer (stages 0 and I) continued to increase, accounting for 65.6% of newly diagnosed cases in 2021. Our results showed that the overall survival rate for patients with breast cancer has improved, primarily due to a rise in early-stage diagnoses and advancements in treatment.

Purpose: The aim of this study was to investigate the efficacy of ethanol extracts of Cornus alba (ECA) against benign prostatic hyperplasia (BPH) in vitro and in vivo. Materials and Methods: The prostate stromal cells (WPMY-1) and epithelial cells (RWPE-1) were used to examine the action mechanism of ECA in BPH in vitro. ECA efficacy was evaluated in vivo using a testosterone propionate (TP)-induced BPH rat model. Results: Treatment with ECA inhibited the proliferation of prostate cells by inducing G1-phase cell cycle arrest through the regulation of positive and negative proteins. Treatment of prostate cells with ECA resulted in alterations in the mitogen-activated protein kinases and protein kinase B signaling pathways. The transcriptional binding activity of the NF-κB motif was suppressed in both ECA-treated prostate cells. In addition, treatment with ECA altered the level of BPH-associated axis markers (5α-reductase, fibroblast growth factor-2, androgen receptor, epidermal growth factor, Bcl-2, and Bax) in both cell lines. Finally, the administration of ECA attenuated the enlargement of prostatic tissues in the TP-induced BPH rat model, accompanied by histology, immunoblot, and serum dihydrotestosterone levels. Conclusions These results demonstrated that ECA exerted beneficial effects on BPH both in vitro and in vivo and might provide valuable information in the development of preventive or therapeutic agents for improving BPH.

Background and Objectives: Lipid lowering therapy is essential to reduce the risk of major cardiovascular events; however, limited evidence exists regarding the use of statin with ezetimibe as primary prevention strategy for middle-aged adults. We aimed to investigate the impact of single pill combination therapy on clinical outcomes in relatively healthy middleaged patients when compared with statin monotherapy. Methods: Using the Korean National Health Insurance Service database, a propensity score match analysis was performed for baseline characteristics of 92,156 patients categorized into combination therapy (n=46,078) and statin monotherapy (n=46,078) groups. Primary outcome was composite outcomes, including death, coronary artery disease, and ischemic stroke. And secondary outcome was all-cause death. The mean follow-up duration was 2.9±0.3 years. Results: The 3-year composite outcomes of all-cause death, coronary artery disease, and ischemic stroke demonstrated no significant difference between the 2 groups (10.3% vs.10.1%; hazard ratio [HR], 1.022; 95% confidence interval [CI], 0.980–1.064; p=0.309).Meanwhile, the 3-year all-cause death rate was lower in the combination therapy group than in the statin monotherapy group (0.2% vs. 0.4%; p<0.001), with a significant HR of 0.595 (95% CI, 0.460–0.769; p<0.001). Single pill combination therapy exhibited consistently lower mortality rates across various subgroups. Conclusions Compared to the statin monotherapy, the combination therapy for primary prevention showed no difference in composite outcomes but may reduce mortality risk in relatively healthy middle-aged patients. However, since the study was observational, further randomized clinical trials are needed to confirm these findings.

Purpose: The aim of this study was to investigate the efficacy of ethanol extracts of Cornus alba (ECA) against benign prostatic hyperplasia (BPH) in vitro and in vivo. Materials and Methods: The prostate stromal cells (WPMY-1) and epithelial cells (RWPE-1) were used to examine the action mechanism of ECA in BPH in vitro. ECA efficacy was evaluated in vivo using a testosterone propionate (TP)-induced BPH rat model. Results: Treatment with ECA inhibited the proliferation of prostate cells by inducing G1-phase cell cycle arrest through the regulation of positive and negative proteins. Treatment of prostate cells with ECA resulted in alterations in the mitogen-activated protein kinases and protein kinase B signaling pathways. The transcriptional binding activity of the NF-κB motif was suppressed in both ECA-treated prostate cells. In addition, treatment with ECA altered the level of BPH-associated axis markers (5α-reductase, fibroblast growth factor-2, androgen receptor, epidermal growth factor, Bcl-2, and Bax) in both cell lines. Finally, the administration of ECA attenuated the enlargement of prostatic tissues in the TP-induced BPH rat model, accompanied by histology, immunoblot, and serum dihydrotestosterone levels. Conclusions These results demonstrated that ECA exerted beneficial effects on BPH both in vitro and in vivo and might provide valuable information in the development of preventive or therapeutic agents for improving BPH.

The Korean Breast Cancer Society (KBCS) has collected nationwide registry data on clinicopathologic characteristics and treatment since 1996. This study aimed to analyze the clinical characteristics of breast cancer in Korea and assess changes in breast cancer statistics for 2021 using data from the KBCS registry and the Korean Central Cancer Registry. In 2021, 34,628 women were newly diagnosed with breast cancer. The median age of women diagnosed with breast cancer was 53.4 years, with the highest incidence occurring in the 40–49 age group. The most common molecular subtype was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative, accounting for 69.1% of cases, while HER2-positive subtypes comprised 19.3%. During the coronavirus disease 2019 pandemic, the national breast cancer screening rate declined. However, the incidence of early-stage breast cancer (stages 0 and I) continued to increase, accounting for 65.6% of newly diagnosed cases in 2021. Our results showed that the overall survival rate for patients with breast cancer has improved, primarily due to a rise in early-stage diagnoses and advancements in treatment.

Background: We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea. Methods: This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated. Results: A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age. Conclusion This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.