1.Risk of non-cancer respiratory diseases attributed to humidifier disinfectant exposure in Koreans: age-period-cohort and differences-in-difference analyses
Jaiyong KIM ; Kyoung Sook JEONG ; Seungyeon HEO ; Younghee KIM ; Jungyun LIM ; Sol YU ; Suejin KIM ; Sun-Kyoung SHIN ; Hae-Kwan CHEONG ; Mina HA ;
Epidemiology and Health 2025;47(1):e2025006-
OBJECTIVES:
Humidifier disinfectants (HDs) were sold in Korea from 1994 until their recall in 2011. We examined the incidence patterns of 8 respiratory diseases before and after the HD recall and estimated the attributable risk in the Korean population.
METHODS:
Using National Health Insurance data from 2002 to 2019, we performed age–cohort–period and differences-in-diffference analyses (comparing periods before vs. after the recall) to estimate the population-attributable fraction and the excess number of episodes. The database comprised 51 million individuals (99% of the Korean population). The incidence of 8 diseases—acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), asthma, pneumonia, chronic sinusitis (CS), interstitial lung disease (ILD), bronchiectasis, and chronic obstructive pulmonary disease (COPD)—was defined by constructing episodes of care based on patterns of medical care and the clinical characteristics of each disease.
RESULTS:
The relative risks (RRs) for AURI, ALRI, asthma, pneumonia, CS, and ILD were elevated among younger individuals (with an RR as high as 82.18 for AURI in males), whereas chronic conditions such as bronchiectasis, COPD, and ILD showed higher RRs in older individuals. During the HD exposure period, the population-attributable risk percentage ranged from 4.6% for bronchiectasis to 25.1% for pneumonia, with the excess number of episodes ranging from 6,218 for ILD to 3,058,861 for CS. Notably, females of reproductive age (19-44 years) experienced 1.1-9.2 times more excess episodes than males.
CONCLUSIONS
This study provides epidemiological evidence that inhalation exposure to HDs affects the entire respiratory tract and identifies vulnerable groups.
2.Risk of non-cancer respiratory diseases attributed to humidifier disinfectant exposure in Koreans: age-period-cohort and differences-in-difference analyses
Jaiyong KIM ; Kyoung Sook JEONG ; Seungyeon HEO ; Younghee KIM ; Jungyun LIM ; Sol YU ; Suejin KIM ; Sun-Kyoung SHIN ; Hae-Kwan CHEONG ; Mina HA ;
Epidemiology and Health 2025;47(1):e2025006-
OBJECTIVES:
Humidifier disinfectants (HDs) were sold in Korea from 1994 until their recall in 2011. We examined the incidence patterns of 8 respiratory diseases before and after the HD recall and estimated the attributable risk in the Korean population.
METHODS:
Using National Health Insurance data from 2002 to 2019, we performed age–cohort–period and differences-in-diffference analyses (comparing periods before vs. after the recall) to estimate the population-attributable fraction and the excess number of episodes. The database comprised 51 million individuals (99% of the Korean population). The incidence of 8 diseases—acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), asthma, pneumonia, chronic sinusitis (CS), interstitial lung disease (ILD), bronchiectasis, and chronic obstructive pulmonary disease (COPD)—was defined by constructing episodes of care based on patterns of medical care and the clinical characteristics of each disease.
RESULTS:
The relative risks (RRs) for AURI, ALRI, asthma, pneumonia, CS, and ILD were elevated among younger individuals (with an RR as high as 82.18 for AURI in males), whereas chronic conditions such as bronchiectasis, COPD, and ILD showed higher RRs in older individuals. During the HD exposure period, the population-attributable risk percentage ranged from 4.6% for bronchiectasis to 25.1% for pneumonia, with the excess number of episodes ranging from 6,218 for ILD to 3,058,861 for CS. Notably, females of reproductive age (19-44 years) experienced 1.1-9.2 times more excess episodes than males.
CONCLUSIONS
This study provides epidemiological evidence that inhalation exposure to HDs affects the entire respiratory tract and identifies vulnerable groups.
3.Risk of non-cancer respiratory diseases attributed to humidifier disinfectant exposure in Koreans: age-period-cohort and differences-in-difference analyses
Jaiyong KIM ; Kyoung Sook JEONG ; Seungyeon HEO ; Younghee KIM ; Jungyun LIM ; Sol YU ; Suejin KIM ; Sun-Kyoung SHIN ; Hae-Kwan CHEONG ; Mina HA ;
Epidemiology and Health 2025;47(1):e2025006-
OBJECTIVES:
Humidifier disinfectants (HDs) were sold in Korea from 1994 until their recall in 2011. We examined the incidence patterns of 8 respiratory diseases before and after the HD recall and estimated the attributable risk in the Korean population.
METHODS:
Using National Health Insurance data from 2002 to 2019, we performed age–cohort–period and differences-in-diffference analyses (comparing periods before vs. after the recall) to estimate the population-attributable fraction and the excess number of episodes. The database comprised 51 million individuals (99% of the Korean population). The incidence of 8 diseases—acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), asthma, pneumonia, chronic sinusitis (CS), interstitial lung disease (ILD), bronchiectasis, and chronic obstructive pulmonary disease (COPD)—was defined by constructing episodes of care based on patterns of medical care and the clinical characteristics of each disease.
RESULTS:
The relative risks (RRs) for AURI, ALRI, asthma, pneumonia, CS, and ILD were elevated among younger individuals (with an RR as high as 82.18 for AURI in males), whereas chronic conditions such as bronchiectasis, COPD, and ILD showed higher RRs in older individuals. During the HD exposure period, the population-attributable risk percentage ranged from 4.6% for bronchiectasis to 25.1% for pneumonia, with the excess number of episodes ranging from 6,218 for ILD to 3,058,861 for CS. Notably, females of reproductive age (19-44 years) experienced 1.1-9.2 times more excess episodes than males.
CONCLUSIONS
This study provides epidemiological evidence that inhalation exposure to HDs affects the entire respiratory tract and identifies vulnerable groups.
4.Risk of non-cancer respiratory diseases attributed to humidifier disinfectant exposure in Koreans: age-period-cohort and differences-in-difference analyses
Jaiyong KIM ; Kyoung Sook JEONG ; Seungyeon HEO ; Younghee KIM ; Jungyun LIM ; Sol YU ; Suejin KIM ; Sun-Kyoung SHIN ; Hae-Kwan CHEONG ; Mina HA ;
Epidemiology and Health 2025;47(1):e2025006-
OBJECTIVES:
Humidifier disinfectants (HDs) were sold in Korea from 1994 until their recall in 2011. We examined the incidence patterns of 8 respiratory diseases before and after the HD recall and estimated the attributable risk in the Korean population.
METHODS:
Using National Health Insurance data from 2002 to 2019, we performed age–cohort–period and differences-in-diffference analyses (comparing periods before vs. after the recall) to estimate the population-attributable fraction and the excess number of episodes. The database comprised 51 million individuals (99% of the Korean population). The incidence of 8 diseases—acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), asthma, pneumonia, chronic sinusitis (CS), interstitial lung disease (ILD), bronchiectasis, and chronic obstructive pulmonary disease (COPD)—was defined by constructing episodes of care based on patterns of medical care and the clinical characteristics of each disease.
RESULTS:
The relative risks (RRs) for AURI, ALRI, asthma, pneumonia, CS, and ILD were elevated among younger individuals (with an RR as high as 82.18 for AURI in males), whereas chronic conditions such as bronchiectasis, COPD, and ILD showed higher RRs in older individuals. During the HD exposure period, the population-attributable risk percentage ranged from 4.6% for bronchiectasis to 25.1% for pneumonia, with the excess number of episodes ranging from 6,218 for ILD to 3,058,861 for CS. Notably, females of reproductive age (19-44 years) experienced 1.1-9.2 times more excess episodes than males.
CONCLUSIONS
This study provides epidemiological evidence that inhalation exposure to HDs affects the entire respiratory tract and identifies vulnerable groups.
5.Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea
Hyundam GU ; Suyoung LEE ; Sol KIM ; Hye-Lim JANG ; Da-Woon CHOI ; Kyu Seok KIM ; Yu Ri SHIN ; Dae Young CHEUNG ; Bo-In LEE ; Jin Il KIM ; Han Hee LEE
Clinical Endoscopy 2024;57(6):790-797
Background/Aims:
Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement.
Methods:
All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings.
Results:
The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved.
Conclusions
This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.
6.Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea
Hyundam GU ; Suyoung LEE ; Sol KIM ; Hye-Lim JANG ; Da-Woon CHOI ; Kyu Seok KIM ; Yu Ri SHIN ; Dae Young CHEUNG ; Bo-In LEE ; Jin Il KIM ; Han Hee LEE
Clinical Endoscopy 2024;57(6):790-797
Background/Aims:
Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement.
Methods:
All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings.
Results:
The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved.
Conclusions
This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.
7.Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea
Hyundam GU ; Suyoung LEE ; Sol KIM ; Hye-Lim JANG ; Da-Woon CHOI ; Kyu Seok KIM ; Yu Ri SHIN ; Dae Young CHEUNG ; Bo-In LEE ; Jin Il KIM ; Han Hee LEE
Clinical Endoscopy 2024;57(6):790-797
Background/Aims:
Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement.
Methods:
All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings.
Results:
The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved.
Conclusions
This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.
8.Effect of Pre- and Post-Dialysis Exercise on Functional Capacity Using Portable Ergometer in Chronic Kidney Disease Patients
Tae-Seok CHAE ; Da-Sol KIM ; Myoung-Hwan KO ; Yu Hui WON
Annals of Rehabilitation Medicine 2024;48(4):239-248
Objective:
To assess whether performing exercises during hemodialysis reduces the risk of developing intradialytic hypotension and enhances exercise capacity in patients with chronic kidney disease.
Methods:
This study included patients aged ≥18 years undergoing hemodialysis. Participants performed exercises using a portable lower extremity ergometer during hemodialysis sessions for 3 weeks. Data regarding walking distance, knee strength, quality of life, fat-free mass, arterial pressure, blood pressure, heart rate, frequency of intradialytic hypotension, fatigue, and duration of hemodialysis were collected and analyzed.
Results:
Significant improvements in walking distance and knee strength were observed following the implementation of exercise training during hemodialysis. Although there was no significant reduction in the frequency of intradialytic hypotension, a decreasing trend was noted. Other parameters such as quality of life and fatigue did not show significant changes.
Conclusion
Using a portable ergometer during hemodialysis improved exercise capacity and knee strength in patients with chronic kidney disease. There was a trend toward reduced intradialytic hypotension, suggesting potential cardiovascular benefits. Further research with larger sample sizes is needed to confirm these findings.
9.Comparison of Synergistic Sedation with Midazolam and Propofol Versus Midazolam and Pethidine in Colonoscopies: A Prospective, Randomized Controlled Study
Jae Woong LIM ; Min Jae KIM ; Gang Han LEE ; Dae Sol KIM ; Sang Hyuk JUNG ; Yu Yeon KIM ; Jin Won KIM ; Yohan LEE ; Hyun Soo KIM ; Seon Young PARK ; Dong Hyun KIM
Chonnam Medical Journal 2024;60(3):192-197
Colonoscopy is a key procedure for the early detection of colorectal cancer. Despite its importance, the discomfort associated with colonoscopy often requires sedation, and the ideal sedation regimen remains to be determined. In this prospective randomized controlled trial, patients scheduled for colonoscopy were randomly assigned to two different sedation protocols. Group A received a combination of midazolam and propofol, while group B was given midazolam and pethidine. The study analyzed data from 51 patients, with 23 in group A and 28 in group B. The incidence of adverse events was similar across both groups. Additionally, no significant differences were observed in cecal intubation times or total procedure durations. Notably, group A had a lower frequency of required postural changes (1.0±0.7 vs. 1.5±0.7, p=0.02) and a reduced rate of manual compression (52.2% vs. 82.1%, p=0.02). There were no significant differences between the groups regarding subjective pain or overall satisfaction. Both sedation regimens were found to be safe and effective. The midazolam and propofol combination was associated with a smoother procedure, evidenced by fewer postural adjustments and less manual compression needed during colonoscopy.
10.Evidence integration on health damage for humidifier disinfectant exposure and legal presumption of causation
Mina HA ; Taehyun PARK ; Jong-Hyun LEE ; Younghee KIM ; Jungyun LIM ; Yong-Wook BAEK ; Sol YU ; Hyen-Mi CHUNG ; Kyu Hyuck CHUNG ; Hae-Kwan CHEONG ;
Epidemiology and Health 2023;45(1):e2023095-
OBJECTIVES:
Inhalation exposure to humidifier disinfectants has resulted to various types of health damages in Korea. To determine the epidemiological correlation necessary for presuming the legal causation, we aimed to develop a method to synthesize the entire evidence.
METHODS:
Epidemiological and toxicological studies are systematically reviewed. Target health problems are selected by criteria such as frequent complaints of claimants. Relevant epidemiologic studies are reviewed and the risk of bias and confidence level of the total evidence are evaluated. Toxicological literature reviews are conducted on three lines of evidence including hazard information, animal studies, and mechanistic studies, considering the source-to-exposure-to-outcome continuum. The confidence level of the body of evidence is then translated into the toxicological evidence levels for the causality between humidifier disinfectant exposure and health effects. Finally, the levels of epidemiological and toxicological evidence are synthesized.
RESULTS:
Under the Special Act revised in 2020, if the history of exposure and the disease occurred/worsened after exposure were approved, and the epidemiological correlation between the exposure and disease was verified, the legal causation is presumed unless the company proves the evidence against it. The epidemiological correlation can be verified through epidemiological investigations, health monitoring, cohort investigations and/or toxicological studies. It is not simply as statistical association as understood in judicial precedents, but a general causation established by the evidence as a whole, i.e., through weight-of-the-evidence approach.
CONCLUSIONS
The weight-of-the-evidence approach differs from the conclusive single study approach and this systematic evidence integration can be used in presumption of causation.

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