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 Information System (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.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: School food service workers are highly likely to develop heat-related illnesses because of their work environment. However, studies that have examined the risk of heat-related illnesses among them are limited. The purpose of this study was to investigate the status of heat exposure, implementation of heat wave countermeasures, and prevalence of heat-related illness symptoms among school food service workers in Korea, and to explore the relationship between them. Methods: A cross-sectional study was conducted through an online survey of school food service workers from May 25 to June 12, 2023, via three labor unions. We analyzed 6,244 valid responses. We assessed general characteristics, heat-related illness symptoms (heat rash, heat cramps, heat edema, heat exhaustion, heat syncope), duration of heat exposure during heat waves, and heat wave preventive measures. Multiple logistic regression analyses were performed, with adjustments for age, occupation, hypertension, diabetes, and school type. Results: More than one-third of school food service workers reported heat exposure between May and September exceeding 4 hours daily, and 94.6% experienced at least one heat-related illness symptom during the last year. A dose-response relationship was observed between heat exposure duration and heat-related illness symptoms (p for trend < 0.001). School food service workers who did not have increased rest periods or did not reduce high-heat prepared foods showed significantly higher odds ratios for heat-related illness symptoms. Conclusions School food service workers experience substantial heat exposure and a high prevalence of heat-related illness symptoms. The risk of heat-related illness symptoms was associated with extended duration of heat exposure. Increasing rest periods and reducing high-heat food preparation were effective preventive measures. These findings underscore the need for improved heat exposure management and implementation of effective preventive measures to protect the health of school food service workers, with particular attention to appropriate rest periods.

Background: and Purpose: Voice, reflecting cerebral functions, holds potential for analyzing and understanding brain function, especially in the context of cognitive impairment (CI) and Alzheimer’s disease (AD). This study used voice data to distinguish between normal cognition and CI or Alzheimer’s disease dementia (ADD). Methods: This study enrolled 3 groups of subjects: 1) 52 subjects with subjective cognitive decline; 2) 110 subjects with mild CI; and 3) 59 subjects with ADD. Voice features were extracted using Mel-frequency cepstral coefficients and Chroma. Results: A deep neural network (DNN) model showed promising performance, with an accuracy of roughly 81% in 10 trials in predicting ADD, which increased to an average value of about 82.0%±1.6% when evaluated against unseen test dataset. Conclusions Although results did not demonstrate the level of accuracy necessary for a definitive clinical tool, they provided a compelling proof-of-concept for the potential use of voice data in cognitive status assessment. DNN algorithms using voice offer a promising approach to early detection of AD. They could improve the accuracy and accessibility of diagnosis, ultimately leading to better outcomes for patients.

Background: Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly. Methods: To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020. Results: In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patientdays was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25–12.05) and 4.18 per 1,000 admissions (range: 1.92–8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68–13.90) and 6.73 per 1,000 admissions (range: 3.18–15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively. Conclusion The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

This study investigated the impact of menopause on the progression and management of common benign gynecological conditions such as polycystic ovary syndrome, endometriosis, uterine fibroids, and adenomyosis. These conditions often present with menstruationrelated symptoms such as irregular cycles, heavy bleeding, and pelvic pain. While these symptoms typically subside after menopause, the underlying pathology of such benign gynecological conditions may be differentially affected by the physiological changes associated with menopause, sometimes leading to exacerbation or additional management challenges. Although rare, the potential for malignant transformation remains a concern. This study aims to elucidate the shifts in management strategies from the reproductive years to postmenopause. It highlights the necessity for a tailored approach to hormone therapy and surgical interventions based on the individual patient’s health profile and the specific characteristics of each condition.

A total of 535 4th∼6th grade students in the Gyeonggi area were surveyed in an effort to increase vegetable preference and intake. They were divided into 3 groups according to the frequency of salad consumption (High-frequency group, HF, more than once a week G; Intermediate-frequency, IFG, 1∼3 times/month;Low-frequency group, LFG, less than once a month). The proportion of subjects who preferred salad over other vegetable dishes was much lower in the LFG than in the other groups. Compared to the HFG, more students in the LFG gave ‘dressing’ as the main reason for their preferring salads, and ‘because of vegetables in salad’ and ‘not knowing the necessity of eating salad’ as the main reasons. Compared to the HFG and MFG, the proportion of students responding ‘less than twice a week’ for vegetable and fruit consumption and ‘more than 2 hours/day on the internet/games’ was higher, while the preferences for namul, salads, saengchae, baechukimchi, chonggakkimchi, nabakkimchi, and fruits were lower in the LFG. The numbers of unfamiliar vegetables and dressings were lower in the HFG than in the other groups and were negatively correlated with the frequency of fruit and vegetable consumption and the preferences for aengchaes, bokkeum, salad, and namul. Also, this study compared the preferences for 14 vegetables and 9 dressings as ingredients of salads by gender, grade, and frequency of eating salads.