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.The efficacy and safety of radiofrequency ablation in papillary thyroid carcinoma: A systematic review and meta-analysis.
Wei Shuen Clarissa CHEONG ; Xin Yi Joy AU ; Ming Yann LIM ; Ernest Weizhong FU ; Hao LI ; Uei PUA ; Yong Quan Alvin SOON ; Yijin Jereme GAN
Annals of the Academy of Medicine, Singapore 2025;54(3):170-177
INTRODUCTION:
Radiofrequency ablation (RFA) avoids the complications of general anaesthesia, reduces length of hospitalisation and reduces morbidity from surgery. As such, it is a strong alternative treatment for patients with comorbidities who are not surgical candidates. However, to our knowledge, there have only been 1 systematic review and 3 combined systematic review and meta-analyses on this topic to date. This systematic review and meta-analysis seeks to evaluate the efficacy and safety of RFA in the treatment of papillary thyroid carcinoma (PTC) with longer follow-up durations.
METHOD:
PubMed, Embase and Cochrane databases were searched for relevant studies published from 1990 to 2021; 13 studies with a total of 1366 patients were included. The Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines and Sandelowski et al.'s approach1 to "negotiated consensual validation" were used to achieve consensus on the final list of articles to be included. All authors then assessed each study using a rating scheme modified from the Oxford Centre for Evidence-Based Medicine.
RESULTS:
Pooled volume reduction rates (VRRs) from 1 to 48 months after RFA, complete disappearance rates (CDR) and complications were assessed. Pooled mean VRRs were 96.59 (95% confidence interval [CI] 91.05-102.13, I2=0%) at 12 months2-6 and 99.31 (95% CI 93.74-104.88, I2=not applicable) at 48 months.2,5 Five studies showed an eventual CDR of 100%.2,4,7-9 No life-threatening complications were recorded. The most common complications included pain, transient voice hoarseness, fever and less commonly, first-degree burn.
CONCLUSION
RFA may be an effective and safe alternative to treating PTC. Larger clinical trials with longer follow-up are needed to further evaluate the effectiveness of RFA in treating PTC.
Humans
;
Radiofrequency Ablation/methods*
;
Thyroid Cancer, Papillary/surgery*
;
Thyroid Neoplasms/surgery*
;
Treatment Outcome
;
Postoperative Complications/etiology*
6.The Role of Education and Demographic Factors in Condom Use among Male Drug Users in Malaysia
Yong Kang Cheah ; Anita Suleiman ; Mazliza Ramly ; Chee Cheong Kee ; Kuang Kuay Lim
Malaysian Journal of Medicine and Health Sciences 2024;20(No.1):52-59
Introduction: The rising prevalence of human immunodeficiency virus (HIV) among people who inject drugs is a
major public health issue. This study intends to explore education and demographic correlates of use of condoms
among male drug users in Malaysia. Methods: Data were extracted from the Integrated Biological and Behavioral
Surveillance Survey 2017. Pearson’s chi-square tests and a logistic regression were used to examine the associations
between condom use and education, and demographic factors. Results: Only a small proportion of drug users used
condoms (25.7%). Educational backgrounds, age, ethnicity and marital status were associated with condom use.
The likelihood of using condoms was lower among less educated drug users (aOR: 0.308–0.339). There was an interaction effect of education and age on condom use (aOR: 0.116–0.308). Chinese (aOR: 3.117) and those of other
ethnicities (aOR: 2.934) were more likely to use condoms when compared with Malays. Being married (aOR: 0.291)
or divorced/widowed (aOR: 0.346) was associated with reduced odds of using condoms. Conclusion: Education and
demographic factors play an important role in influencing the decisions of Malaysian drug users to use condoms.
Therefore, HIV-preventive measures targeting drug users could benefit by paying special attention to these factors.
7.Costs Associated with Transcatheter Aortic Valve Implantation and Surgical Aortic Valve Replacement in Korea
Suk Ho SOHN ; Kyung Hwan KIM ; Yoonjin KANG ; Jae Woong CHOI ; Seung Hyun LEE ; Sung Ho SHINN ; Jae Suk YOO ; Cheong LIM
Journal of Chest Surgery 2024;57(6):536-546
Background:
This study compared the costs associated with transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) in Korea by utilizing the National Health Insurance Service database.
Methods:
Between June 2015 and May 2019, 1,468 patients underwent primary isolated transfemoral TAVI, while 2,835 patients received primary isolated SAVR with a bioprosthesis. We assessed the costs of index hospitalization and subsequent healthcare utilization, categorizing the cohort into 6 age subgroups: <70, 70–74, 75–79, 80–84, 85–89, and ≥90 years. The median follow-up periods were 2.5 and 3.0 years in the TAVI and SAVR groups, respectively.
Results:
The index hospitalization costs were 41.0 million Korean won (KRW) (interquartile range [IQR], 39.1–44.7) for the TAVI group and 24.6 million KRW (IQR, 21.3–30.2) for the SAVR group (p<0.001). The TAVI group exhibited relatively constant index hospitalization costs across different age subgroups. In contrast, the SAVR group showed increasing index hospitalization costs with advancing age. The healthcare utilization costs were 5.7 million KRW per year (IQR, 3.3–14.2) for the TAVI group and 4.0 million KRW per year (IQR, 2.2–9.0) for the SAVR group (p<0.001). Healthcare utilization costs were higher in the TAVI group than in the SAVR group for the age subgroups of <70, 70–74, and 75–79 years, and were comparable in the age subgroups of 80–84, 85–89, and ≥90 years.
Conclusion
TAVI had much higher index hospitalization costs than SAVR. Additionally, the overall healthcare utilization costs post-discharge for TAVI were also marginally higher than those for SAVR in younger age subgroups.
8.Toxicological properties of Technekitty injection (Tc-99m) in diagnosing feline hyperthyroidism
Jae Cheong LIM ; So-Young LEE ; Eun Ha CHO ; Yu Mi JUNG ; Ki Hwan PARK ; Young Uk PARK ; Sung Soo NAM ; Tae Hoon LEE ; Jae Won LEE ; Yiseul CHOI ; Inki LEE ; Yeon CHAE ; Byeong-Teck KANG
Journal of Biomedical and Translational Research 2024;25(4):201-210
Following the previous study, which investigated the pharmacological properties of the Technekitty injection (Tc-99m), the toxicity of a single intravenous administration of the Technekittyinjection (Tc-99m) and the side effects that may occur at the diagnostic dose were confirmed.The Technekitty injection (Tc-99m) was administered intravenously once at a dose of 0, 0.67, 2.0, and 6.0 mCi/kg to 5 male and female rats per group. Mortality, general symptom obser-vation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. No abnormal systemic signs related to the Technekitty injection (Tc-99m) were observed. These results confirmed that Technekitty injection (Tc-99m) can be safely admin-istered intravenously at doses up to 6.0 mCi/kg. Additionally, technetium-99m at an average dose of 2 mCi (74 MBq) has been verified as a diagnostic dose without adverse effects, al-lowing the Technekitty injection (Tc-99m) to be used safely without side effects at this dosage.This study demonstrates that the Technekitty injection (Tc-99m) has a wide safety margin, supporting its potential for clinical application. Moreover, these findings align with the nonclin-ical safety standards for radiopharmaceuticals, reinforcing its utility in veterinary medicine.The Technekitty injection (Tc-99m) is expected to be applicable for clinical diagnosis as a vet-erinary drug in Korea.
9.Pharmacological properties of Technekitty injection (Tc-99m) in diagnosing feline hyperthyroidism
Jae Cheong LIM ; So-Young LEE ; Eun Ha CHO ; Yu Mi JUNG ; Ki Hwan PARK ; Young Uk PARK ; Sung Soo NAM ; Tae Hoon LEE ; Jae Won LEE ; Jisu SUN ; Hye Kyung CHUNG ; Yong Jin LEE ; Yeon CHAE ; Byeong-Teck KANG
Journal of Biomedical and Translational Research 2024;25(4):185-199
Thyroid scanning using technetium-99m ( 99mTc) is the gold standard for diagnosing feline hyperthyroidism. In cats with an overactive thyroid, a thyroid scan is the most appropriate imaging technique to detect and localize any hyperfunctional adenomatous thyroid tissue. In this study, the pharmacological properties of the Technekitty injection (Tc-99m), developed as a diagnostic agent for feline hyperthyroidism using 99mTc as an active ingredient, were tested in FRTL-5 thyroid follicular cell line and ICR mice. The percentage of cell uptake of the Tc-99m in FRTL-5 thyroid cells was 0.182 ± 0.018%, which was about 6 times higher compared to Clone 9 hepatocytes. This uptake decreased by 38.2% due to competitive inhibition by iodine (sodium iodide). In tissue distribution tests by using ICR mice, the highest distribution was observed in the liver, kidneys, spleen, lungs, and femur at 0.083 hours after administration, and this distribution decreased as the compound was excreted through the kidneys, the pri-mary excretory organ. Maximum distribution was confirmed at 1 hour in the small intestine, 6hours in the large intestine, and 2 hours in the thyroid gland. Additionally, the total amount excreted through urine and feces over 48 hours (2 days) was 78.80% of the injected dose, with 37.70% (47.84% of the total excretion) excreted through urine and 41.10% (52.16% of the total excretion) through feces. In conclusion, the Tc-99m has the same mechanism of action, potency, absorption, distribution, metabolism, and excretion characteristics as 99mTc used for feline hyperthyroidism in the United States, Europe, and other countries, because the Technekitty injection (Tc-99m) contains 99mTc as its sole active ingredient. Based on these results, the Technekitty injection (Tc-99m) is expected to be safely used in the clinical diagnosis of feline hyperthyroidism.
10.Toxicological evidence integration to confirm the biological plausibility of the association between humidifier disinfectant exposure and respiratory diseases using the AEP-AOP framework
Ha Ryong KIM ; Jun Woo KIM ; Jong-Hyeon LEE ; Younghee KIM ; Jungyun LIM ; Yong-Wook BAEK ; Sunkyoung SHIN ; Mina HA ; Hae-Kwan CHEONG ; Kyu Hyuck CHUNG ;
Epidemiology and Health 2024;46(1):e2024060-
OBJECTIVES:
Exposure to humidifier disinfectants has been linked to respiratory diseases, including interstitial lung disease, asthma, and pneumonia. Consequently, numerous toxicological studies have explored respiratory damage as both a necessary and sufficient condition for these diseases. We systematically reviewed and integrated evidence from toxicological studies by applying the evidence integration method established in previous research to confirm the biological plausibility of the association between exposure and disease.
METHODS:
We conducted a literature search focusing on polyhexamethylene guanidine phosphate (PHMG) and chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT), the primary ingredients in humidifier disinfectants. We selected relevant studies based on their quality and the population, exposure, comparator, outcome (PECO) statements. These studies were categorized into three lines of evidence: hazard information, animal studies, and mechanistic studies. Based on a systematic review, we integrated the evidence to develop an aggregate exposure pathway–adverse outcome pathway (AEP-AOP) model for respiratory damage. The reliability and relevance of our findings were assessed by comparing them with the hypothesized pathogenic mechanisms of respiratory diseases.
RESULTS:
By integrating toxicological evidence for each component of the AEP-AOP framework for PHMG and CMIT/MIT, we developed an AEP-AOP model that elucidates how disinfectants released from humidifiers expose target sites, triggering molecular initiating events and key events that ultimately lead to respiratory damage. This model exhibits high reliability and relevance to the pathogenesis of respiratory diseases.
CONCLUSIONS
The AEP-AOP model developed in this study provides strong evidence, based on evidence-based toxicology, that exposure to humidifier disinfectants causes respiratory diseases. This model demonstrates the pathways leading to respiratory damage, a hallmark of these conditions.


Result Analysis
Print
Save
E-mail