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.Self-Reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire
Hee Kyung YANG ; Shin Hae PARK ; Haeng-Jin LEE ; Sook-Young KIM ; Hyo Jung GYE ; So Young KIM ; Sun Young SHIN ; Key Hwan LIM ;
Korean Journal of Ophthalmology 2024;38(3):194-202
Purpose:
To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population.
Methods:
The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS.
Results:
The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery.
Conclusions
The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.
6.Impacts of Subtype on Clinical Feature and Outcome of Male Breast Cancer: Multicenter Study in Korea (KCSG BR16-09)
Jieun LEE ; Keun Seok LEE ; Sung Hoon SIM ; Heejung CHAE ; Joohyuk SOHN ; Gun Min KIM ; Kyung-Hee LEE ; Su Hwan KANG ; Kyung Hae JUNG ; Jae-ho JEONG ; Jae Ho BYUN ; Su-Jin KOH ; Kyoung Eun LEE ; Seungtaek LIM ; Hee Jun KIM ; Hye Sung WON ; Hyung Soon PARK ; Guk Jin LEE ; Soojung HONG ; Sun Kyung BAEK ; Soon Il LEE ; Moon Young CHOI ; In Sook WOO
Cancer Research and Treatment 2023;55(1):123-135
Purpose:
The treatment of male breast cancer (MBC) has been extrapolated from female breast cancer (FBC) because of its rarity despite their different clinicopathologic characteristics. We aimed to investigate the distribution of intrinsic subtypes based on immunohistochemistry, their clinical impact, and treatment pattern in clinical practice through a multicenter study in Korea.
Materials and Methods:
We retrospectively analyzed clinical data of 248 MBC patients from 18 institutions across the country from January 1995 to July 2016.
Results:
The median age of MBC patients was 63 years (range, 25 to 102 years). Among 148 intrinsic subtype classified patients, 61 (41.2%), 44 (29.7%), 29 (19.5%), and 14 (9.5%) were luminal A, luminal B, human epidermal growth factor receptor 2, and triple-negative breast cancer, respectively. Luminal A subtype showed trends for superior survival compared to other subtypes. Most hormone receptor-positive patients (166 patients, 82.6%) received adjuvant endocrine treatment. Five-year completion of adjuvant endocrine treatment was associated with superior disease-free survival (DFS) in patients classified with an intrinsic subtype (hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04 to 0.49; p=0.002) and in all patients (HR, 0.16; 95% CI, 0.05 to 0.54; p=0.003).
Conclusion
Distribution of subtypes of MBC was similar to FBC and luminal type A was most common. Overall survival tended to be improved for luminal A subtype, although there was no statistical significance. Completion of adjuvant endocrine treatment was associated with prolonged DFS in intrinsic subtype classified patients. MBC patients tended to receive less treatment. MBC patients should receive standard treatment according to guidelines as FBC patients.
7.Clinical Characteristics and Risk Factors for Mortality in Critical COVID-19 Patients Aged 50 Years or Younger During Omicron Wave in Korea:Comparison With Patients Older Than 50 Years of Age
Hye Jin SHI ; Jinyoung YANG ; Joong Sik EOM ; Jae-Hoon KO ; Kyong Ran PECK ; Uh Jin KIM ; Sook In JUNG ; Seulki KIM ; Hyeri SEOK ; Miri HYUN ; Hyun Ah KIM ; Bomi KIM ; Eun-Jeong JOO ; Hae Suk CHEONG ; Cheon Hoo JUN ; Yu Mi WI ; Jungok KIM ; Sungmin KYM ; Seungjin LIM ; Yoonseon PARK
Journal of Korean Medical Science 2023;38(28):e217-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has caused the death of thousands of patients worldwide. Although age is known to be a risk factor for morbidity and mortality in COVID-19 patients, critical illness or death is occurring even in the younger age group as the epidemic spreads. In early 2022, omicron became the dominant variant of the COVID-19 virus in South Korea, and the epidemic proceeded on a large scale. Accordingly, this study aimed to determine whether young adults (aged ≤ 50 years) with critical COVID-19 infection during the omicron period had different characteristics from older patients and to determine the risk factors for mortality in this specific age group.
Methods:
We evaluated 213 critical adult patients (high flow nasal cannula or higher respiratory support) hospitalized for polymerase chain reaction-confirmed COVID-19 in nine hospitals in South Korea between February 1, 2022 and April 30, 2022. Demographic characteristics, including body mass index (BMI) and vaccination status; underlying diseases; clinical features and laboratory findings; clinical course; treatment received; and outcomes were collected from electronic medical records (EMRs) and analyzed according to age and mortality.
Results:
Overall, 71 critically ill patients aged ≤ 50 years were enrolled, and 142 critically ill patients aged over 50 years were selected through 1:2 matching based on the date of diagnosis. The most frequent underlying diseases among those aged ≤ 50 years were diabetes and hypertension, and all 14 patients who died had either a BMI ≥ 25 kg/m 2 or an underlying disease. The total case fatality rate among severe patients (S-CFR) was 31.0%, and the S-CFR differed according to age and was higher than that during the delta period. The S-CFR was 19.7% for those aged ≤ 50 years, 36.6% for those aged > 50 years, and 38.1% for those aged ≥ 65 years. In multivariate analysis, age (odds ratio [OR], 1.084; 95% confidence interval [CI], 1.043–1.127), initial low-density lipoprotein > 600 IU/L (OR, 4.782; 95% CI, 1.584–14.434), initial C-reactive protein > 8 mg/dL (OR, 2.940; 95% CI, 1.042–8.293), highest aspartate aminotransferase > 200 IU/L (OR, 12.931; 95% CI, 1.691–98.908), and mechanical ventilation implementation (OR, 3.671; 95% CI, 1.294–10.420) were significant independent predictors of mortality in critical COVID-19 patients during the omicron wave. A similar pattern was shown when analyzing the data by age group, but most had no statistical significance owing to the small number of deaths in the young critical group. Although the vaccination completion rate of all the patients (31.0%) was higher than that in the delta wave period (13.6%), it was still lower than that of the general population. Further, only 15 (21.1%) critically ill patients aged ≤ 50 years were fully vaccinated. Overall, the severity of hospitalized critical patients was significantly higher than that in the delta period, indicating that it was difficult to find common risk factors in the two periods only with a simple comparison.
Conclusion
Overall, the S-CFR of critically ill COVID-19 patients in the omicron period was higher than that in the delta period, especially in those aged ≤ 50 years. All of the patients who died had an underlying disease or obesity. In the same population, the vaccination rate was very low compared to that in the delta wave, indicating that non-vaccination significantly affected the progression to critical illness. Notably, there was a lack of prescription for Paxlovid for these patients although they satisfied the prescription criteria. Early diagnosis and active initial treatment was necessary, along with the proven methods of vaccination and personal hygiene. Further studies are needed to determine how each variant affects critically ill patients.
8.Clinical Characteristics and Risk Factors for Mortality in Critical Coronavirus Disease 2019 Patients 50 Years of Age or Younger During the Delta Wave: Comparison With Patients > 50 Years in Korea
Hye Jin SHI ; Eliel NHAM ; Bomi KIM ; Eun-Jeong JOO ; Hae Suk CHEONG ; Shin Hee HONG ; Miri HYUN ; Hyun ah KIM ; Sukbin JANG ; Ji-Young RHEE ; Jungok KIM ; Sungmin KIM ; Hyun Kyu CHO ; Yu Mi WI ; Shinhye CHEON ; Yeon-Sook KIM ; Seungjin LIM ; Hyeri SEOK ; Sook In JUNG ; Joong Sik EOM ; Kyong Ran PECK
Journal of Korean Medical Science 2022;37(22):e175-
Background:
Numerous patients around the globe are dying from coronavirus disease 2019 (COVID-19). While age is a known risk factor, risk analysis in the young generation is lacking. The present study aimed to evaluate the clinical features and mortality risk factors in younger patients (≤ 50 years) with a critical case of COVID-19 in comparison with those among older patients (> 50 years) in Korea.
Methods:
We analyzed the data of adult patients only in critical condition (requiring high flow nasal cannula oxygen therapy or higher respiratory support) hospitalized with PCR-confirmed COVID-19 at 11 hospitals in Korea from July 1, 2021 to November 30, 2021 when the delta variant was a dominant strain. Patients’ electronic medical records were reviewed to identify clinical characteristics.
Results:
During the study period, 448 patients were enrolled. One hundred and forty-two were aged 50 years or younger (the younger group), while 306 were above 50 years of age (the older group). The most common pre-existing conditions in the younger group were diabetes mellitus and hypertension, and 69.7% of the patients had a body mass index (BMI) > 25 kg/m 2 .Of 142 younger patients, 31 of 142 patients (21.8%, 19 women) did not have these pre-existing conditions. The overall case fatality rate among severity cases was 21.0%, and it differed according to age: 5.6% (n = 8/142) in the younger group, 28.1% in the older group, and 38% in the ≥ 65 years group. Age (odds ratio [OR], 7.902; 95% confidence interval [CI], 2.754–18.181), mechanical ventilation therapy (OR, 17.233; 95% CI, 8.439–35.192), highest creatinine > 1.5 mg/dL (OR, 17.631; 95% CI, 8.321–37.357), and combined blood stream infection (OR, 7.092;95% CI, 1.061–18.181) were identified as independent predictors of mortality in total patients.Similar patterns were observed in age-specific analyses, but most results were statistically insignificant in multivariate analysis due to the low number of deaths in the younger group.The full vaccination rate was very low among study population (13.6%), and only three patients were fully vaccinated, with none of the patients who died having been fully vaccinated in the younger group. Seven of eight patients who died had a pre-existing condition or were obese (BMI > 25 kg/m 2 ), and the one remaining patient died from a secondary infection.
Conclusion
About 22% of the patients in the young critical group did not have an underlying disease or obesity, but the rate of obesity (BMI > 25 kg/m2 ) was high, with a fatality rate of 5.6%. The full vaccination rate was extremely low compared to the general population of the same age group, showing that non-vaccination has a grave impact on the progression of COVID-19 to a critical condition. The findings of this study highlight the need for measures to prevent critical progression of COVID-19, such as vaccinations and targeting young adults especially having risk factors.
9.Impact of Current Alcohol Consumption on Cognitive Function in Patients with Self-Perceived Memory Decline: A Comparative Study of Subjective Cognitive Decline, Mild Cognitive Impairment and Alzheimer-Type Dementia Groups
Hyun Joung LIM ; Mi Yeon KIM ; Jung Won SHIN ; Kang Soo LEE ; Jung Hae YOUN ; Bo Mi PARK ; Ji Hong LEE ; Hyun Sook KIM
Journal of the Korean Neurological Association 2022;40(1):29-38
Background:
Alcohol consumption has been considered as a modifiable risk factor for dementia development and alcohol-related brain damage may further impair cognitive abilities in dementia patients. This study aimed to find out the differences in cognitive function according to current alcohol drinking in patients with self-perceived memory decline, including subjective cognitive decline (SCD), mild cognitive impairment (MCI) and early Alzheimer-type dementia (ATD).
Methods:
From May 2018 to December 2019, retrospective chart review was performed in patients who visited CHA Bundang Medical Center for cognitive decline. A two-way analysis of variance with interaction test were used to analyze the impact of alcohol consumption on cognitive function between groups.
Results:
A total of 147 patients was classified into three groups of SCD (n=30), MCI (n=53), and ATD (n=64), and each group was divided into two subgroups of alcohol users and alcohol non-users, according to the current status of alcohol consumption. Between SCD, MCI and ATD groups, scores of clock drawing test and Go/No-go test were significantly lower in current alcohol users of ATD groups compared to the SCD and MCI groups (p<0.05).
Conclusions
These results suggest that current alcohol consumption has detrimental effects especially on the frontal/executive function in early ATD patients. Considering the association between frontal/executive function and ADL, our finding suggests that cessation of alcohol intake may be a therapeutic strategy to prevent ADL deterioration in patients with ATD.
10.Operation and Process Evaluation of a Community Meal Program for the Elderly in Rural Areas during Agricultural Off-Season Perceived by Cooking Volunteers
Jeong Sook BAE ; Sol Bee SEONG ; So Mang JANG ; Chang Hee YOO ; Young Suk LIM ; Young Mi LEE ; Hae Ryun PARK ; Kyung Eun LEE
Korean Journal of Community Nutrition 2019;24(4):277-289
OBJECTIVES: This study examined the practices of a community meal program for older adults in rural areas during the agricultural off-season. METHODS: A survey was conducted from December 12 to December 22, 2016. Self-administered questionnaires were distributed to 150 cooking volunteers, who had participated in the community meal program in 50 villages. A total of 114 responses were returned from 44 villages and used for data analysis. In addition, in-depth interviews were conducted with the volunteers of eight villages. RESULTS: Most of the cooking volunteers were 50 years old or older and they participated in serving older adults meals for good will. The cooking volunteers perceived that the older adults in their community did not eat various foods, had difficulties in grocery shopping, and frequently consumed salty foods. During the agricultural off-season, 40.9% of villages served the older adults meals 6–7 days a week and 95.5% provided meals for lunch. An average of 21 to 40 older adults were served meals in each village. The cooking volunteers reported that the food preparation and meal service times were sufficient, recipes provided were useful, and menus met the preference of the older adults. At the end of the program, they felt proud of serving meals for older adults in the community. An increased awareness of healthy eating, interest in health, and consumption of nutritious meals, a decrease in loneliness among older adults, and the promotion of fellowship in the community were rated highly. The cooking volunteers expected additional support for cooking personnel and insisted that the program should be provided for the entire agricultural off-seasons. CONCLUSIONS: The community meal program during the agricultural off-season for the elderly in rural areas was effective in improving the dietary life of older adults, relieving their feelings of isolation, and promoting fellowship of the community. The volunteers felt workload due to a shortage of volunteers but answered that they were rewarded by helping older adults in their community.
Adult
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Aged
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Cooking
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Eating
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Fellowships and Scholarships
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Humans
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Loneliness
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Lunch
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Meals
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Reward
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Statistics as Topic
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Volunteers

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