Epidemiology and Health

Original article

Evaluation of gestational age by pregnancy outcomes and distribution of pregnancy-related codes in Korean claims data: Woo-Jung Kim, Yunha Noh, Youngtai Cho, Eun-Young Choi, HyunJoo Lim, Hyesung Lee, Ju-Young Shin; Epidemiol Health. 2026;e2026007. Published online February 4, 2026; DOI: https://doi.org/10.4178/epih.e2026007 [Accepted]

140 View
9 Download

Abstract PDF: Abstract
OBJECTIVES
This study aimed to evaluate a fixed-duration algorithm for gestational age (GA) estimation according to pregnancy outcomes and to describe the GA distribution of pregnancy-related codes in Korea.
METHODS
We included 351,055 pregnancy episodes (2019–2022) from linked data between the National Health Insurance Service and the Korea Immunization Registry (KIRIS). GA from claims data was estimated by subtracting fixed durations from the delivery date (algorithm-based GA), and GA derived from KIRIS was defined as the gold standard. Accuracy was evaluated as the proportion of episodes in which the difference between the estimated GA and the reference standard fell within ±2 weeks. We described the distributions of the GA at which each prenatal test, pregnancy complication, and diagnostic code was recorded.
RESULTS
Algorithm-based GA estimation showed high accuracy for live births (92.2% within ±2 weeks) but markedly lower accuracy for non–live-birth outcomes, including stillbirth (3.3%), termination (7.2%), spontaneous abortion (45.2%), and ectopic pregnancy (20.0%). In additional analyses aimed at identifying potential indicators for improving GA estimation, most events occurred within clinically expected timeframes, although some individual codes exhibited poor temporal alignment.
CONCLUSIONS
Algorithm-based GA estimation using claims data performed well for live births but demonstrated limited accuracy for non–live-birth outcomes. Incorporating information from prenatal tests and pregnancy complications may enhance GA estimation.; Summary

Correspondence

Authors’ Reply: Safety of combination therapy of azilsartan medoxomil and amlodipine: a population-based cohort study: Hyesung Lee, Bin Hong, Chris Tzu-Ting Su, Sungho Bea, Han Eol Jeong, Kyungyeon Jung, Michael Chun-Yuan Cheng, Zoe Chi-Jui Chang, Edward Chia-Cheng Lai, Jongyoung Lee; Epidemiol Health. 2025;47:e2025054. Published online September 20, 2025; DOI: https://doi.org/10.4178/epih.e2025054

2,420 View
70 Download

PDF: Abstract; Summary

Original Articles

Safety of combination therapy of azilsartan medoxomil and amlodipine: a population-based cohort study: Hyesung Lee, Bin Hong, Chris Tzu-Ting Su, Sungho Bea, Han Eol Jeong, Kyungyeon Jung, Michael Chun-Yuan Cheng, Zoe Chi-Jui Chang, Edward Chia-Cheng Lai, Jongyoung Lee; Epidemiol Health. 2025;47:e2025029. Published online May 28, 2025; DOI: https://doi.org/10.4178/epih.e2025029

7,935 View
186 Download
2 Web of Science
2 Crossref

Abstract Summary PDF Supplementary Material

Abstract

OBJECTIVES
This study investigated the safety of azilsartan and amlodipine combination therapy versus other angiotensin receptor blockers (ARBs) and amlodipine in patients with hypertension.

METHODS

We conducted a cohort study utilizing healthcare databases from Korea and Taiwan. Patients aged between 18 years and 75 years who were newly prescribed both an ARB and amlodipine within 6 months of hypertension diagnosis were included. Safety outcomes assessed were hypotension, angioedema, acute pancreatitis, hyperkalemia, hypokalemia, toxic liver disease, hepatic failure, nausea and vomiting, and fall-related injury. Hazard ratios (HRs) with 95% confidence intervals (CIs) for each safety outcome associated with azilsartan medoxomil and amlodipine versus other ARBs combined with amlodipine were calculated within a 1:1 propensity score (PS)-matched cohort. Summary HRs across databases were computed using random-effects meta-analysis.

RESULTS

We identified 2,472 eligible patients (1,521 from Korea, 951 from Taiwan) initiating treatment with azilsartan medoxomil and amlodipine, and 671,468 patients (312,322 from Korea, 355,409 from Taiwan) initiating other ARBs with amlodipine. After PS matching, baseline characteristics were well-balanced between treatment groups. During the 180-day follow-up, most adverse outcomes did not occur even once in either group, thus precluding the calculation of HRs. The risk of acute pancreatitis was not significantly different between the azilsartan medoxomil and amlodipine group and the other ARB and amlodipine groups (summary HR, 0.86; 95% CI, 0.14 to 5.37).

CONCLUSIONS

In this population-based cohort study, azilsartan medoxomil combined with amlodipine was not associated with an increased risk of adverse outcomes compared to other ARBs combined with amlodipine.

Summary

Korean summary
Azilsartan medoxomil과 amlodipine 병용요법의 장기적인 안전성을 평가한 연구는 제한적임. 본 코호트 연구에서는 azilsartan과 amlodipine 병용요법이 다른 ARB-amlodipine 병용요법에 비해 중대한 이상반응 발생 위험을 증가시키지 않는 것으로 나타났음. 이러한 결과는 고혈압 환자에서 azilsartan-amlodipine 병용요법의 실제 진료 환경에서의 안전성을 뒷받침함.

Key Message
Limited studies have evaluated the long-term safety of combined azilsartan medoxomil and amlodipine therapy. This cohort study found the azilsartan and amlodipine combination therapy was not associated with increased risk of serious adverse events compared to other ARB-amlodipine combinations. These results support the real-world safety of azilsartan-amlodipine caombination therapy in patients with hypertension.

Citations

Citations to this article as recorded by

Letter to the Editor: Safety of combination therapy of azilsartan medoxomil and amlodipine: a population-based cohort study
Zhanyi Zhou
Epidemiology and Health.2025; 47: e2025053. CrossRef
Authors’ Reply: Safety of combination therapy of azilsartan medoxomil and amlodipine: a population-based cohort study
Hyesung Lee, Bin Hong, Chris Tzu-Ting Su, Sungho Bea, Han Eol Jeong, Kyungyeon Jung, Michael Chun-Yuan Cheng, Zoe Chi-Jui Chang, Edward Chia-Cheng Lai, Jongyoung Lee
Epidemiology and Health.2025; 47: e2025054. CrossRef

Long working hours and the risk of hypothyroidism in healthy Korean workers: a cohort study: Yesung Lee, Woncheol Lee, Hyoung-Ryoul Kim; Epidemiol Health. 2022;44:e2022104. Published online November 8, 2022; DOI: https://doi.org/10.4178/epih.e2022104

16,544 View
236 Download
2 Web of Science
2 Crossref

Abstract Summary PDF Supplementary Material

Abstract

OBJECTIVES
Long working hours have been reported to cause various health problems, but are currently practiced in many countries. Building upon a previous cross-sectional study, the authors aimed to elucidate the causal relationship between long working hours and hypothyroidism through a longitudinal study.

METHODS

Data were collected at baseline from 45,259 participants without thyroid disease and with consistent weekly working hours (36-40, 41-52, 53-60, and >60 hours) during the follow-up period. Hypothyroidism was defined using the reference limits of serum thyroid-stimulating hormone and free thyroxine levels. By estimating hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analysis, the risk of incident hypothyroidism was evaluated with 36-40 hours of work per week as the reference.

RESULTS

During 138,261.7 person-years of follow-up, 2,914 participants developed hypothyroidism (incidence density, 2.11/102 person-years). The multivariable-adjusted HRs of incident hypothyroidism for 41-52 hours, 53-60 hours, and >60 hours of work per week were 1.13 (95% CI, 1.03 to 1.24), 2.53 (95% CI, 2.17 to 2.95), and 2.57 (95% CI, 2.09 to 3.15), respectively. In dose-response analyses, long working hours had an approximately linear relationship with hypothyroidism incidence. The risk of incident hypothyroidism in those who worked 53-60 hours and >60 hours per week compared with the reference group was significantly higher among the older age group (≥36 years, stratified by median age), men, and daytime workers.

CONCLUSIONS

This large-scale cohort study demonstrated the association between long working hours and an increased risk of incident hypothyroidism with a dose-response relationship.

Summary

Korean summary
대규모 코호트연구를 통해 장시간노동을 수행한 노동자들에서 갑상선기능저하증의 위험이 높아지는 것을 확인할 수 있었다. 특히 연령, 성, 교대근무 유무에 따라 층화하여 분석한 결과에서 고연령, 남성, 교대근무를 하지 않는 노동자에서 관련성의 크기가 증가하였다.

Key Message
This large-scale cohort study (The Kangbuk Samsung Health Study), which used 45,259 participants without thyroid disease at baseline and estimated hazard ratios (HRs) using Cox proportional hazards regression analysis, demonstrated the association between long working hours and an increased risk of incident hypothyroidism with a dose-response relationship especially in older age group, men, and daytime workers.

Citations

Citations to this article as recorded by

Effectiveness of Physical Activity-Led Workplace Health Promotion Interventions: A Systematic Review
Shichao Zhang, Mingjian Nie, Jiale Peng, Hong Ren
Healthcare.2025; 13(11): 1292. CrossRef
Association between shift work and the risk of hypothyroidism in adult male workers in Korea: a cohort study
Seonghyeon Kwon, Yesung Lee, Eunhye Seo, Daehoon Kim, Jaehong Lee, Youshik Jeong, Jihoon Kim, Jinsook Jeong, Woncheol Lee
Annals of Occupational and Environmental Medicine.2023;[Epub] CrossRef

Clinical outcomes of COVID-19 following the use of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers among patients with hypertension in Korea: a nationwide study: Ju Hwan Kim, Yeon-Hee Baek, Hyesung Lee, Young June Choe, Hyun Joon Shin, Ju-Young Shin; Epidemiol Health. 2021;43:e2021004. Published online December 29, 2020; DOI: https://doi.org/10.4178/epih.e2021004

39,548 View
460 Download
11 Web of Science
10 Crossref

Abstract Summary PDF

Abstract

OBJECTIVES
Recent evidence has shown no harm associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) in patients with coronavirus disease 2019 (COVID-19). We sought to further clarify the possible association between ACEI/ARB use and the risk of poor clinical outcomes of COVID-19.

METHODS

From the completely enumerated COVID-19 cohort in Korea, we identified 1,290 patients with hypertension, of whom 682 had and 603 did not have records of ACEI/ARB use during the 30-day period before their COVID-19 diagnosis. Our primary endpoint comprised clinical outcomes, including all-cause mortality, use of mechanical ventilation, intensive care unit admission, and sepsis. We used inverse probability of treatment weighting (IPTW) to mitigate selection bias, and a Poisson regression model to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for comparing outcomes between ACEI/ARB users and non-users.

RESULTS

Compared to non-use, ACEI/ARB use was associated with lower clinical outcomes (IPTW-adjusted RR, 0.60; 95% CI, 0.42 to 0.85; p=0.005). For individual outcomes, ACEI/ARB use was not associated with all-cause mortality (IPTW-adjusted RR, 0.62; 95% CI, 0.35 to 1.09; p=0.097) or respiratory events (IPTW-adjusted RR, 0.99; 95% CI, 0.84 to 1.17; p=0.904). Subgroup analysis showed a trend toward a protective role of ACEIs and ARBs against overall outcomes in men (IPTW-adjusted RR, 0.84; 95% CI, 0.69 to 1.03; p<sub>interaction</sub>=0.008) and patients with pre-existing respiratory disease (IPTW-adjusted RR, 0.74; 95% CI, 0.60 to 0.92; p<sub>interaction</sub>=0.002).

CONCLUSIONS

We present clinical evidence to support continuing ACE/ARB use in COVID-19 patients with hypertension based on the completely enumerated Korean cohort.

Summary

Korean summary
– 코로나-19 검사를 받은 69,793명 중에 코로나-19 양성이며 고혈압이 있는 1,290명을 연구대상자로 선정했으며, 이중 코로나-19 진단일로부터 30일이내에 ACEI 또는 ARB를 사용한 환자는 682명이었음. – ACEI 또는 ARB 사용은 비사용 대비 사망 또는 폐 관련 질환의 위험과의 관련성이 없었음. – 하위그룹 분석에서 남성 또는 기저 폐질환 보유 환자에서 ACEI 또는 ARB 사용이 코로나-19 예후 악화를 예방하는 트렌드를 보였음.

Key Message
– Among 69,793 individuals screened for COVID-19, we identified 1,290 patients with hypertension who tested positive, of whom 682 had records of using ACEIs or ARBs in the 30 days before their COVID-19 diagnosis. – ACEI/ARB use (compared with non-use) was not associated with all-cause mortality or respiratory events. – A subgroup analysis showed a trend toward a protective role of ACEIs and ARBs against the overall composite endpoint of poor outcomes in men and those with pre-existing respiratory disease.

Citations

Citations to this article as recorded by

A Meta-Analysis of the Impact of Using Angiotensin-Converting Enzyme Inhibitors (ACEIs) or Angiotensin II Receptor Blockers (ARBs) on Mortality, Severity, and Healthcare Resource Utilization in Patients with COVID-19
Ruijuan Li, Jie Zhang, Liang Ren
Advances in Respiratory Medicine.2025; 93(1): 4. CrossRef
Systematic review and meta-analysis of the clinical outcomes of ACEI/ARB in East-Asian patients with COVID-19
Nancy Xurui Huang, Qi Yuan, Fang Fang, Bryan P. Yan, John E. Sanderson, Masaki Mogi
PLOS ONE.2023; 18(1): e0280280. CrossRef
COVID-19 Therapeutics Why Not Angiotensin Receptor Blockers (ARBs)?
Hariharan T S
Journal of the Association of Physicians of India.2023; 71(11): 71. CrossRef
Mortality and Severity in COVID-19 Patients on ACEIs and ARBs—A Systematic Review, Meta-Analysis, and Meta-Regression Analysis
Romil Singh, Sawai Singh Rathore, Hira Khan, Abhishek Bhurwal, Mack Sheraton, Prithwish Ghosh, Sohini Anand, Janaki Makadia, Fnu Ayesha, Kiran S. Mahapure, Ishita Mehra, Aysun Tekin, Rahul Kashyap, Vikas Bansal
Frontiers in Medicine.2022;[Epub] CrossRef
Renin‐Angiotensin Aldosterone System Inhibitors and COVID‐19: A Systematic Review and Meta‐Analysis Revealing Critical Bias Across a Body of Observational Research
Jordan Loader, Frances C. Taylor, Erik Lampa, Johan Sundström
Journal of the American Heart Association.2022;[Epub] CrossRef
Drugs acting on the renin–angiotensin–aldosterone system (RAAS) and deaths of COVID-19 patients: a systematic review and meta-analysis of observational studies
Ruchika Sharma, Anoop Kumar, Jaseela Majeed, Ajit K. Thakur, Geeta Aggarwal
The Egyptian Heart Journal.2022;[Epub] CrossRef
Acute motor-sensory axonal polyneuropathy variant of Guillain–Barre syndrome complicating the recovery phase of coronavirus disease 2019 infection: a case report
Ahmed Maseh Haidary, Sarah Noor, Esmatullah Hamed, Tawab Baryali, Soma Rahmani, Maryam Ahmad, Farahnaz Erfani, Hashmatullah Azimi, Habib Ul Rahman Habib, Gul Ahmad Tahiri, Ramin Saadaat, Abdul Sami Ibrahimkhil, Esmatullah Esmat, Haider Ali Malakzai
Journal of Medical Case Reports.2021;[Epub] CrossRef
Renin‐Angiotensin Aldosterone System Inhibitors in Primary Prevention and COVID‐19
Jordan Loader, Erik Lampa, Stefan Gustafsson, Thomas Cars, Johan Sundström
Journal of the American Heart Association.2021;[Epub] CrossRef
Role of Hypertension on the Severity of COVID-19: A Review
Mei Peng, Jia He, Ying Xue, Xue Yang, Shao Liu, Zhicheng Gong
Journal of Cardiovascular Pharmacology.2021; 78(5): e648. CrossRef
COVID-19, the Pandemic of the Century and Its Impact on Cardiovascular Diseases
Yuanyuan Zhang, Mingjie Wang, Xian Zhang, Tianxiao Liu, Peter Libby, Guo-Ping Shi
Cardiology Discovery.2021; 1(4): 233. CrossRef

First
Prev
Page of 1
Next
Last

Search