1.Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study
Suyeon KIM ; Hwa Yeon KO ; Jeongin OH ; Dongwon YOON ; Ju Hwan KIM ; Young June CHOE ; Ju-Young SHIN ; On behalf of the CoVaSC Investigators
Journal of Korean Medical Science 2025;40(3):e10-
Background:
Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established.
Methods:
We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition.
Results:
Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis.
Conclusion
The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.
2.Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study
Suyeon KIM ; Hwa Yeon KO ; Jeongin OH ; Dongwon YOON ; Ju Hwan KIM ; Young June CHOE ; Ju-Young SHIN ; On behalf of the CoVaSC Investigators
Journal of Korean Medical Science 2025;40(3):e10-
Background:
Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established.
Methods:
We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition.
Results:
Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis.
Conclusion
The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.
3.Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study
Suyeon KIM ; Hwa Yeon KO ; Jeongin OH ; Dongwon YOON ; Ju Hwan KIM ; Young June CHOE ; Ju-Young SHIN ; On behalf of the CoVaSC Investigators
Journal of Korean Medical Science 2025;40(3):e10-
Background:
Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established.
Methods:
We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition.
Results:
Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis.
Conclusion
The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.
4.Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study
Suyeon KIM ; Hwa Yeon KO ; Jeongin OH ; Dongwon YOON ; Ju Hwan KIM ; Young June CHOE ; Ju-Young SHIN ; On behalf of the CoVaSC Investigators
Journal of Korean Medical Science 2025;40(3):e10-
Background:
Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established.
Methods:
We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition.
Results:
Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis.
Conclusion
The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.
5.2023 Clinical Practice Guidelines for Diabetes Management in Korea: Full Version Recommendation of the Korean Diabetes Association
Jun Sung MOON ; Shinae KANG ; Jong Han CHOI ; Kyung Ae LEE ; Joon Ho MOON ; Suk CHON ; Dae Jung KIM ; Hyun Jin KIM ; Ji A SEO ; Mee Kyoung KIM ; Jeong Hyun LIM ; Yoon Ju SONG ; Ye Seul YANG ; Jae Hyeon KIM ; You-Bin LEE ; Junghyun NOH ; Kyu Yeon HUR ; Jong Suk PARK ; Sang Youl RHEE ; Hae Jin KIM ; Hyun Min KIM ; Jung Hae KO ; Nam Hoon KIM ; Chong Hwa KIM ; Jeeyun AHN ; Tae Jung OH ; Soo-Kyung KIM ; Jaehyun KIM ; Eugene HAN ; Sang-Man JIN ; Jaehyun BAE ; Eonju JEON ; Ji Min KIM ; Seon Mee KANG ; Jung Hwan PARK ; Jae-Seung YUN ; Bong-Soo CHA ; Min Kyong MOON ; Byung-Wan LEE
Diabetes & Metabolism Journal 2024;48(4):546-708
6.Real-World Treatment Patterns according to Clinical Practice Guidelines in Patients with Type 2 Diabetes Mellitus and Established Cardiovascular Disease in Korea: Multicenter, Retrospective, Observational Study
Ye Seul YANG ; Nam Hoon KIM ; Jong Ha BAEK ; Seung-Hyun KO ; Jang Won SON ; Seung-Hwan LEE ; Sang Youl RHEE ; Soo-Kyung KIM ; Tae Seo SOHN ; Ji Eun JUN ; In-Kyung JEONG ; Chong Hwa KIM ; Keeho SONG ; Eun-Jung RHEE ; Junghyun NOH ; Kyu Yeon HUR ;
Diabetes & Metabolism Journal 2024;48(2):279-289
Background:
Recent diabetes management guidelines recommend that sodium-glucose cotransporter 2 inhibitors (SGLT2is) or glucagon-like peptide 1 receptor agonists (GLP-1RAs) with proven cardiovascular benefits should be prioritized for combination therapy in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease (CVD). This study was aimed at evaluating SGLT2i or GLP-1RA usage rates and various related factors in patients with T2DM and established CVD.
Methods:
We enrolled adults with T2DM aged ≥30 years who were hospitalized due to established CVD from January 2019 to May 2020 at 13 secondary and tertiary hospitals in Korea in this retrospective observational study.
Results:
Overall, 2,050 patients were eligible for analysis among 2,107 enrolled patients. The mean patient age, diabetes duration, and glycosylated hemoglobin level were 70.0 years, 12.0 years, and 7.5%, respectively. During the mean follow-up duration of 9.7 months, 25.7% of the patients were prescribed SGLT2is after CVD events. However, only 1.8% were prescribed GLP-1RAs. Compared with SGLT2i non-users, SGLT2i users were more frequently male and obese. Furthermore, they had a shorter diabetes duration but showed worse glycemic control and better renal function at the time of the event. GLP-1RA users had a longer duration of diabetes and worse glycemic control at the time of the event than GLP-1RA non-users.
Conclusion
The SGLT2i or GLP-1RA prescription rates were suboptimal in patients with T2DM and established CVD. Sex, body mass index, diabetes duration, glycemic control, and renal function were associated with the use of these agents.
7.Treatment Patterns and Persistence Among Patients Newly Diagnosed With Migraine in South Korea: A Retrospective Analysis of Health Claims Data
Ki Yeon KIM ; Hwa Yeon KO ; Sungho BEA ; Ho-Jin LEE ; Ju-Young SHIN ; Min Kyung CHU
Journal of Clinical Neurology 2024;20(5):529-536
Background:
and Purpose Migraine is one of the most common chronic neurological diseases worldwide. Although diverse treatment regimens have been recommended, there is insufficient evidence for which treatment patterns to apply in routine clinical settings.
Methods:
We used nationwide claims data from South Korea for 2015–2021 to identify incident migraine patients with at least one prescription for migraine. Patients were categorized according to their initial treatment classes and followed up from the date of treatment initiation. Treatment regimens included prophylactic treatments (antidepressants, anticonvulsants, beta blockers, calcium-channel blockers, and renin-angiotensin-aldosterone system [RAAS] inhibitors) and acute treatments (acetaminophen, antiemetics, aspirin, ergotamine, nonsteroidal anti-inflammatory drugs [NSAIDs], opioids, and triptans). The treatment patterns of migraine were evaluated until the end of the study period, including the secular trends, prevalence, persistence, and changes in migraine treatment.
Results:
Among the 761,350 included patients who received migraine treatment, the most frequently prescribed acute treatment was an NSAID (69.9%), followed by acetaminophen (50.0%).The most-prescribed prophylactic treatment was flunarizine (36.9%), followed by propranolol (24.4%). Among the patients, 54.8% received acute treatment, 13.5% received prophylactic treatment, and 31.6% received both treatment types. However, 65.7% of the patients discontinued their treatment within 3 months. The 3-month persistence rate was highest for triptans (25.2%) among the acute treatments and for RAAS inhibitors (62.0%) among the prophylactic treatments.
Conclusions
While the prevalence rates of medication use were found to align with current migraine guidelines, frequent switching and rapid discontinuation of drugs were observed in routine clinical settings.
8.Contemporary Statistics of Acute Ischemic Stroke and Transient Ischemic Attack in 2021: Insights From the CRCS-K-NIH Registry
Do Yeon KIM ; Tai Hwan PARK ; Yong-Jin CHO ; Jong-Moo PARK ; Kyungbok LEE ; Minwoo LEE ; Juneyoung LEE ; Sang Yoon BAE ; Da Young HONG ; Hannah JUNG ; Eunvin KO ; Hyung Seok GUK ; Beom Joon KIM ; Jun Yup KIM ; Jihoon KANG ; Moon-Ku HAN ; Sang-Soon PARK ; Keun-Sik HONG ; Hong-Kyun PARK ; Jeong-Yoon LEE ; Byung-Chul LEE ; Kyung-Ho YU ; Mi Sun OH ; Dong-Eog KIM ; Dong-Seok GWAK ; Soo Joo LEE ; Jae Guk KIM ; Jun LEE ; Doo Hyuk KWON ; Jae-Kwan CHA ; Dae-Hyun KIM ; Joon-Tae KIM ; Kang-Ho CHOI ; Hyunsoo KIM ; Jay Chol CHOI ; Joong-Goo KIM ; Chul-Hoo KANG ; Sung-il SOHN ; Jeong-Ho HONG ; Hyungjong PARK ; Sang-Hwa LEE ; Chulho KIM ; Dong-Ick SHIN ; Kyu Sun YUM ; Kyusik KANG ; Kwang-Yeol PARK ; Hae-Bong JEONG ; Chan-Young PARK ; Keon-Joo LEE ; Jee Hyun KWON ; Wook-Joo KIM ; Ji Sung LEE ; Hee-Joon BAE ;
Journal of Korean Medical Science 2024;39(34):e278-
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 noncardioembolic 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.
9.2023 Clinical Practice Guidelines for Diabetes Mellitus of the Korean Diabetes Association
Jong Han CHOI ; Kyung Ae LEE ; Joon Ho MOON ; Suk CHON ; Dae Jung KIM ; Hyun Jin KIM ; Nan Hee KIM ; Ji A SEO ; Mee Kyoung KIM ; Jeong Hyun LIM ; YoonJu SONG ; Ye Seul YANG ; Jae Hyeon KIM ; You-Bin LEE ; Junghyun NOH ; Kyu Yeon HUR ; Jong Suk PARK ; Sang Youl RHEE ; Hae Jin KIM ; Hyun Min KIM ; Jung Hae KO ; Nam Hoon KIM ; Chong Hwa KIM ; Jeeyun AHN ; Tae Jung OH ; Soo-Kyung KIM ; Jaehyun KIM ; Eugene HAN ; Sang-Man JIN ; Won Suk CHOI ; Min Kyong MOON ; ;
Diabetes & Metabolism Journal 2023;47(5):575-594
In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.
10.Barriers to COVID-19 vaccine surveillance: the issue of under-reporting adverse events
Yunha NOH ; Hwa Yeon KO ; Ju Hwan KIM ; Dongwon YOON ; Young June CHOE ; Seung-Ah CHOE ; Jaehun JUNG ; Ju-Young SHIN
Epidemiology and Health 2023;45(1):e2023054-
OBJECTIVES:
This study investigated the reporting rates of adverse events following immunization (AEFIs) to the spontaneous reporting system (SRS) and its predictors among individuals with AEFIs after coronavirus disease 2019 (COVID-19) vaccination.
METHODS:
A cross-sectional, web-based survey was conducted from December 2, 2021 to December 20, 2021, recruiting participants >14 days after completion of a primary COVID-19 vaccination series. Reporting rates were calculated by dividing the number of participants who reported AEFIs to the SRS by the total number of participants who experienced AEFIs. We estimated adjusted odds ratios (aORs) using multivariate logistic regression to determine factors associated with spontaneous AEFIs reporting.
RESULTS:
Among 2,993 participants, 90.9% and 88.7% experienced AEFIs after the first and second vaccine doses, respectively (reporting rates, 11.6 and 12.7%). Furthermore, 3.3% and 4.2% suffered moderate to severe AEFIs, respectively (reporting rates, 50.5 and 50.0%). Spontaneous reporting was more prevalent in female (aOR, 1.54; 95% confidence interval [CI], 1.31 to 1.81); those with moderate to severe AEFIs (aOR, 5.47; 95% CI, 4.45 to 6.73), comorbidities (aOR, 1.31; 95% CI, 1.09 to 1.57), a history of severe allergic reactions (aOR, 2.02; 95% CI, 1.47 to 2.77); and those who had received mRNA-1273 (aOR, 1.25; 95% CI, 1.05 to 1.49) or ChAdOx1 (aOR, 1.62; 95% CI, 1.15 to 2.30) vaccines versus BNT162b2. Reporting was less likely in older individuals (aOR, 0.98; 95% CI, 0.98 to 0.99 per 1-year age increment).
CONCLUSIONS
Spontaneous reporting of AEFIs after COVID-19 vaccination was associated with younger age, female sex, moderate to severe AEFIs, comorbidities, history of allergic reactions, and vaccine type. AEFIs under-reporting should be considered when delivering information to the community and in public health decision-making.

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