1.Real-World Utilization Patterns of Oral Corticosteroids During Pregnancy:A Nationwide Population-Based Study in Korea
Jeongin OH ; Yongtai CHO ; Jung Yeol HAN ; Ahhyung CHOI ; Ju-Young SHIN
Journal of Korean Medical Science 2025;40(2):e80-
Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.
2.Real-World Utilization Patterns of Oral Corticosteroids During Pregnancy:A Nationwide Population-Based Study in Korea
Jeongin OH ; Yongtai CHO ; Jung Yeol HAN ; Ahhyung CHOI ; Ju-Young SHIN
Journal of Korean Medical Science 2025;40(2):e80-
Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.
3.Real-World Utilization Patterns of Oral Corticosteroids During Pregnancy:A Nationwide Population-Based Study in Korea
Jeongin OH ; Yongtai CHO ; Jung Yeol HAN ; Ahhyung CHOI ; Ju-Young SHIN
Journal of Korean Medical Science 2025;40(2):e80-
Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.
4.Real-World Utilization Patterns of Oral Corticosteroids During Pregnancy:A Nationwide Population-Based Study in Korea
Jeongin OH ; Yongtai CHO ; Jung Yeol HAN ; Ahhyung CHOI ; Ju-Young SHIN
Journal of Korean Medical Science 2025;40(2):e80-
Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.
5.COVID-19 infection and severe clinical outcomes in patients with kidney disease by vaccination status: a nationwide cohort study in Korea
Jieun WOO ; Ahhyung CHOI ; Jaehun JUNG ; Ju-Young SHIN
Epidemiology and Health 2024;46(1):e2024065-
OBJECTIVES:
Patients with kidney disease have been prioritized for coronavirus disease 2019 (COVID-19) vaccination due to their susceptibility to COVID-19 infection. However, little evidence exists regarding these patients’ vulnerability to COVID-19 post-vaccination. Thus, we evaluated the risk of COVID-19 in patients with kidney disease compared to individuals without kidney disease according to vaccination status.
METHODS:
A retrospective cohort study was conducted using the Korean nationwide COVID-19 registry linked with National Health Insurance Service claims data (2018-2021). Among individuals aged 12 years or older, 2 separate cohorts were constructed: a COVID-19-vaccinated cohort and an unvaccinated cohort. Within each cohort, the risk of COVID-19 infection and all-cause mortality, hospitalization, and emergency room visits within 30 days of COVID-19 infection were compared between patients with and without kidney disease. To adjust for potential confounding, we used propensity score matching. Hazard ratios (HRs) for each outcome were estimated using a Cox proportional hazard model.
RESULTS:
We identified 785,390 and 836,490 individuals in the vaccinated and unvaccinated cohorts, respectively. Compared to patients without kidney disease, patients with kidney disease were at a higher risk of COVID-19 infection in both the vaccinated cohort (HR, 1.08; 95% confidence interval [CI], 1.02 to 1.16) and the unvaccinated cohort (HR, 1.09; 95% CI, 0.99 to 1.20). Likewise, patients with kidney disease generally were at higher risk for severe clinical outcomes within 30 days of COVID-19 infection. Subgroup and sensitivity analyses showed generally consistent results.
CONCLUSIONS
Our study observed excess risk of COVID-19 in patients with kidney disease, highlighting the importance of ongoing attention to these patients even post-vaccination.
6.COVID-19 infection and severe clinical outcomes in patients with kidney disease by vaccination status: a nationwide cohort study in Korea
Jieun WOO ; Ahhyung CHOI ; Jaehun JUNG ; Ju-Young SHIN
Epidemiology and Health 2024;46(1):e2024065-
OBJECTIVES:
Patients with kidney disease have been prioritized for coronavirus disease 2019 (COVID-19) vaccination due to their susceptibility to COVID-19 infection. However, little evidence exists regarding these patients’ vulnerability to COVID-19 post-vaccination. Thus, we evaluated the risk of COVID-19 in patients with kidney disease compared to individuals without kidney disease according to vaccination status.
METHODS:
A retrospective cohort study was conducted using the Korean nationwide COVID-19 registry linked with National Health Insurance Service claims data (2018-2021). Among individuals aged 12 years or older, 2 separate cohorts were constructed: a COVID-19-vaccinated cohort and an unvaccinated cohort. Within each cohort, the risk of COVID-19 infection and all-cause mortality, hospitalization, and emergency room visits within 30 days of COVID-19 infection were compared between patients with and without kidney disease. To adjust for potential confounding, we used propensity score matching. Hazard ratios (HRs) for each outcome were estimated using a Cox proportional hazard model.
RESULTS:
We identified 785,390 and 836,490 individuals in the vaccinated and unvaccinated cohorts, respectively. Compared to patients without kidney disease, patients with kidney disease were at a higher risk of COVID-19 infection in both the vaccinated cohort (HR, 1.08; 95% confidence interval [CI], 1.02 to 1.16) and the unvaccinated cohort (HR, 1.09; 95% CI, 0.99 to 1.20). Likewise, patients with kidney disease generally were at higher risk for severe clinical outcomes within 30 days of COVID-19 infection. Subgroup and sensitivity analyses showed generally consistent results.
CONCLUSIONS
Our study observed excess risk of COVID-19 in patients with kidney disease, highlighting the importance of ongoing attention to these patients even post-vaccination.
7.COVID-19 infection and severe clinical outcomes in patients with kidney disease by vaccination status: a nationwide cohort study in Korea
Jieun WOO ; Ahhyung CHOI ; Jaehun JUNG ; Ju-Young SHIN
Epidemiology and Health 2024;46(1):e2024065-
OBJECTIVES:
Patients with kidney disease have been prioritized for coronavirus disease 2019 (COVID-19) vaccination due to their susceptibility to COVID-19 infection. However, little evidence exists regarding these patients’ vulnerability to COVID-19 post-vaccination. Thus, we evaluated the risk of COVID-19 in patients with kidney disease compared to individuals without kidney disease according to vaccination status.
METHODS:
A retrospective cohort study was conducted using the Korean nationwide COVID-19 registry linked with National Health Insurance Service claims data (2018-2021). Among individuals aged 12 years or older, 2 separate cohorts were constructed: a COVID-19-vaccinated cohort and an unvaccinated cohort. Within each cohort, the risk of COVID-19 infection and all-cause mortality, hospitalization, and emergency room visits within 30 days of COVID-19 infection were compared between patients with and without kidney disease. To adjust for potential confounding, we used propensity score matching. Hazard ratios (HRs) for each outcome were estimated using a Cox proportional hazard model.
RESULTS:
We identified 785,390 and 836,490 individuals in the vaccinated and unvaccinated cohorts, respectively. Compared to patients without kidney disease, patients with kidney disease were at a higher risk of COVID-19 infection in both the vaccinated cohort (HR, 1.08; 95% confidence interval [CI], 1.02 to 1.16) and the unvaccinated cohort (HR, 1.09; 95% CI, 0.99 to 1.20). Likewise, patients with kidney disease generally were at higher risk for severe clinical outcomes within 30 days of COVID-19 infection. Subgroup and sensitivity analyses showed generally consistent results.
CONCLUSIONS
Our study observed excess risk of COVID-19 in patients with kidney disease, highlighting the importance of ongoing attention to these patients even post-vaccination.
8.COVID-19 infection and severe clinical outcomes in patients with kidney disease by vaccination status: a nationwide cohort study in Korea
Jieun WOO ; Ahhyung CHOI ; Jaehun JUNG ; Ju-Young SHIN
Epidemiology and Health 2024;46(1):e2024065-
OBJECTIVES:
Patients with kidney disease have been prioritized for coronavirus disease 2019 (COVID-19) vaccination due to their susceptibility to COVID-19 infection. However, little evidence exists regarding these patients’ vulnerability to COVID-19 post-vaccination. Thus, we evaluated the risk of COVID-19 in patients with kidney disease compared to individuals without kidney disease according to vaccination status.
METHODS:
A retrospective cohort study was conducted using the Korean nationwide COVID-19 registry linked with National Health Insurance Service claims data (2018-2021). Among individuals aged 12 years or older, 2 separate cohorts were constructed: a COVID-19-vaccinated cohort and an unvaccinated cohort. Within each cohort, the risk of COVID-19 infection and all-cause mortality, hospitalization, and emergency room visits within 30 days of COVID-19 infection were compared between patients with and without kidney disease. To adjust for potential confounding, we used propensity score matching. Hazard ratios (HRs) for each outcome were estimated using a Cox proportional hazard model.
RESULTS:
We identified 785,390 and 836,490 individuals in the vaccinated and unvaccinated cohorts, respectively. Compared to patients without kidney disease, patients with kidney disease were at a higher risk of COVID-19 infection in both the vaccinated cohort (HR, 1.08; 95% confidence interval [CI], 1.02 to 1.16) and the unvaccinated cohort (HR, 1.09; 95% CI, 0.99 to 1.20). Likewise, patients with kidney disease generally were at higher risk for severe clinical outcomes within 30 days of COVID-19 infection. Subgroup and sensitivity analyses showed generally consistent results.
CONCLUSIONS
Our study observed excess risk of COVID-19 in patients with kidney disease, highlighting the importance of ongoing attention to these patients even post-vaccination.
9.Safety of COVID-19 Vaccination During Pregnancy and Lactation: A VigiBase Analysis
Dayeon KANG ; Ahhyung CHOI ; Suneun PARK ; Seung-Ah CHOE ; Ju-Young SHIN
Journal of Korean Medical Science 2024;39(1):e3-
Background:
There is limited evidence on the safety of coronavirus disease 2019 (COVID-19) vaccination during pregnancy and lactation. Thus, we aimed to evaluate the association between COVID-19 vaccination during pregnancy and lactation and reporting risk of adverse pregnancy or lactation outcomes.
Methods:
Using VigiBase, we performed a disproportionality analysis with caseon case design. Cases were defined based on the Standardized MedDRA Queries (SMQs) of “pregnancy and neonatal topics” and non-cases were defined as all other adverse events. We included all reports with COVID-19 vaccines as the suspected cause. Using the full database as the comparators, reporting odds ratios (RORs) with 95% confidence intervals (CIs) were estimated by logistic regression while adjusting for maternal age. Infants’ age and sex were additionally adjusted in analyzing the risk of COVID-19 vaccination during lactation.
Results:
We identified 10,266 and 6,474 reports with the SMQ of “pregnancy and neonatal topics” associated with COVID-19 vaccines during pregnancy and lactation, respectively. No significant RORs of adverse pregnancy outcomes associated with COVID-19 vaccines during pregnancy were observed; however, “functional lactation disorders” showed significant disproportionality during lactation with adjusted ROR of 1.48 (95% CI, 1.21–1.79). Further analysis that analyzed “functional lactation disorders” at a preferred term level, showed higher ROR in mastitis (2.76 [95% CI, 1.45–5.27]).
Conclusion
Overall, we did not observe a positive association between COVID-19 vaccination during pregnancy and risk of reporting adverse pregnancy outcomes. However, we found a significant disproportionate reporting association between COVID-19 vaccination during lactation and “functional lactation disorders”, specifically mastitis. Continuous surveillance is warranted to confirm the safety of COVID-19 vaccine during pregnancy and lactation.
10.Adverse Pregnancy and Child Outcomes in Oral Retinoid-Exposed Pregnancies: A Nationwide Population-Based Study
Wonkyoung YOU ; Ahhyung CHOI ; Hyesung LEE ; Jung Yeol HAN ; Ji Hyun LEE ; Ju-Young SHIN
Journal of Korean Medical Science 2024;39(26):e201-
Background:
Oral retinoids are used to treat various dermatological conditions, and their use is increasing in women of childbearing age. However, there is limited knowledge on the incidence of adverse outcomes after retinoid exposure during pregnancy. We aimed to evaluate the risk of adverse outcomes associated with oral retinoid exposure during pregnancy.
Methods:
We conducted a retrospective cohort study using the NHIS mother-child linked healthcare database in South Korea. We included all women who gave live birth from April 1, 2009 to December 31, 2020 and their children. The exposure was defined as having ≥ 1 prescription of isotretinoin, alitretinoin, and acitretin from one month before pregnancy to the delivery. The outcomes of interest were adverse child outcomes including major congenital malformations, low birth weight, and neurodevelopmental disorders (autism spectrum disorder and intellectual disorder), and adverse pregnancy outcomes including gestational diabetes mellitus, preeclampsia, and postpartum hemorrhage. Propensity score-based matching weights were used to control for various potential confounders. For congenital malformation, low birth weight, and adverse pregnancy outcomes, we calculated relative risk (RR) with 95% confidence interval (CI) using a generalized linear model and for neurodevelopmental disorders, we estimated hazard ratio (HR) with 95% CI using the Cox proportional hazard model.
Results:
Of 3,894,184 pregnancies, we identified 720 pregnancies (0.02%) as the oral retinoid-exposed group. The incidence of major congenital malformation was 400.6 per 10,000 births for oral retinoid-exposed group and 357.9 per 10,000 births for unexposed group and the weighted RR was 1.10 (95% CI, 0.65–1.85) in oral retinoid-exposed group compared with unexposed group. The neurodevelopmental disorder showed a potential increased risk, with the weighted HR of 1.63 (95% CI, 0.60–4.41) for autism spectrum disorder and 1.71 (95% CI, 0.60–4.93) for the intellectual disorder, although it did not reach statistical significance. For low birth weight and adverse pregnancy outcomes, no association was observed with oral retinoid exposure during pregnancy.
Conclusion
This study found no significantly increased risk of congenital malformations, autism spectrum disorders, and intellectual disability associated with oral retinoid exposure during pregnancy; however, given the limitations such as including only the live births and increased point estimate, potential risk cannot be fully excluded.

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