Journal of Korean Medical Science最新文献

{"title":"Characteristics, Healthcare Utilization, and Medical Expenditures of Home-Based Primary Care Users in Korea.","authors":"Chang-O Kim, Hye Yeon Koo, Jae-Ryun Lee, Sunyoung Kim, Dongmin Seo, Soong-Nang Jang, Jong Lull Yoon, Hyejin Lee","doi":"10.3346/jkms.2026.41.e224","DOIUrl":"10.3346/jkms.2026.41.e224","url":null,"abstract":"<p><strong>Background: </strong>To address the unmet health needs of recipients of the long-term care (LTC) insurance system, a home-based primary care (HBPC) pilot program was introduced in Korea in 2022. This study investigated the characteristics of LTC recipients who used HBPC.</p><p><strong>Methods: </strong>This retrospective study used data from the National Health Insurance Service database. We identified all individuals who were assigned LTC grades from December 2022 to June 2024 (study period) in Korea and classified them according to their HBPC use. A total of 959,182 LTC recipients were included as the study population. Differences in baseline characteristics and healthcare utilization during the study period between HBPC users and non-users were compared. Multivariate logistic regression analysis was performed to evaluate the association between baseline characteristics and HBPC use.</p><p><strong>Results: </strong>Among the study population, 8,487 (0.9%) were HBPC users and 950,695 (99.1%) were non-users. Emergency room visits were more frequent in HBPC users than in non-users. However, there was no difference in hospitalization rates, and hospitalization-related expenses were lower among HBPC users. Factors associated with HBPC use in the logistic regression analysis were male sex, low income, residing in the Seoul metropolitan region, more severe LTC grade, absence of disability, lower Charlson Comorbidity Index, and presence of dementia or cancer. Additionally, individuals with geriatric syndrome or a higher Multimorbidity Frailty Index were more likely to use HBPC.</p><p><strong>Conclusion: </strong>This study showed that HBPC is more actively used by LTC recipients with high-need and high-risk; who have a low income; live in the Seoul metropolitan region; and have dementia, cancer, or geriatric syndromes.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e224"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503050/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Machine Learning Models for Anxiety Levels Assessment in Patients With Breast Cancer Using Self-Questionnaires.","authors":"Taewoo Kang, Eunsoo Moon, Kyungwon Kim, Hyunju Lim, Hwagyu Suh, Kyoung-Eun Kim, Heeseung Park","doi":"10.3346/jkms.2026.41.e211","DOIUrl":"10.3346/jkms.2026.41.e211","url":null,"abstract":"<p><strong>Background: </strong>This study aimed to develop a machine-learning model using self-report questionnaires to screen for clinically significant anxiety symptoms in patients with breast cancer experiencing severe distress.</p><p><strong>Methods: </strong>A cohort of 327 breast cancer clinic patients was included. Anxiety symptoms were evaluated using the State-Trait Anxiety Inventory-State (STAI-S), State-Trait Anxiety Inventory-Trait (STAI-T), Beck Anxiety Inventory (BAI), and Hospital Anxiety and Depression Scale (HADS) questionnaires. The high-risk anxiety group was determined based on the Mini International Neuropsychiatric Interview Patient Health Survey. Supervised machine learning models were analyzed and validated using MATLAB2022.</p><p><strong>Results: </strong>The BAI showed an area under the curve (AUC) of 0.782 with the logistic regression classifier. The HADS showed an AUC of 0.784 with linear discriminant analysis. STAI-S and STAI-T exhibited AUCs of 0.770 and 0.791, respectively, using Support Vector Machine with a linear kernel. Models combining multiple questionnaires yielded higher AUCs: STAI-S and STAI-T combined resulted in 0.807, STAI-S and BAI in 0.794, STAI-T and BAI in 0.808, and the combination of STAI-S, STAI-T, and BAI achieved 0.810.</p><p><strong>Conclusion: </strong>The combination models demonstrated superior performance in detecting anxiety among patients with breast cancer compared to individual questionnaires. Combining multiple self-report scales enhances screening accuracy, indicating future research should optimize these models further through integration with other methodologies.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e211"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503054/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in Mental Health Networks Among High-Risk Suicide Groups in Korea Before and After the COVID-19 Pandemic.","authors":"Jeong Hun Yang, Dae Hun Kang, C Hyung Keun Park, Sang Jin Rhee, Min Ji Kim, Hyun Jeong Lee, Sang Yeol Lee, Chan-Mo Yang, Se-Hoon Shim, Jung-Joon Moon, Seong-Jin Cho, Shin Gyeom Kim, Min-Hyuk Kim, Jinhee Lee, Won Sub Kang, Jieun Yoo, Weon-Young Lee, Yong Min Ahn","doi":"10.3346/jkms.2026.41.e216","DOIUrl":"10.3346/jkms.2026.41.e216","url":null,"abstract":"<p><strong>Background: </strong>Suicide remains a critical global public health issue, and the coronavirus disease 2019 (COVID-19) pandemic has intensified mental health challenges, potentially increasing suicide risk. This study aimed to analyze the changes in mental health networks of high-risk suicide groups in Korea before and after the COVID-19 pandemic.</p><p><strong>Methods: </strong>Using data from the Korean Cohort for the Model Predicting Suicide and Suicide-Related Behavior, we analyzed 1,179 participants, including individuals with recent suicide attempts and those experiencing suicidal ideation. Network analysis was conducted using EBICglasso algorithms separately for men and women before and after the COVID-19 pandemic, to examine the relationships between key mental health variables including depression (Patient Health Questionnaire-9), anxiety (Beck Anxiety Inventory), stress (Stress Questionnaire for Korean National Health and Nutrition Examination Survey-Short Form), impulsivity (Barratt Impulsiveness Scale-11), and suicidal ideation (Columbia-Suicide Severity Rating Scale).</p><p><strong>Results: </strong>After the pandemic, significant increases in the severity and intensity of suicidal ideation were observed in both sexes (<i>P</i> < 0.001). Overall network connectivity decreased, while strong interconnections between depression, anxiety, and stress persisted in both sexes. After the pandemic, betweenness centrality increased for anxiety in women and depression in men. The bootstrapped edge-weighted confidence intervals mostly remained within acceptable thresholds (< 0.2), ensuring network reliability.</p><p><strong>Conclusion: </strong>The COVID-19 pandemic has led to structural changes in the mental health network of high-risk suicide groups, with anxiety emerging as a more central factor in women and depression in men, highlighting them as key intervention targets. These findings underscore the need for tailored mental health strategies to mitigate suicide risk in populations affected by the pandemic.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e216"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503055/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical and Criminal Characteristics of Patients With Schizophrenia Exhibiting Homicidal and Non-Homicidal Behavior: A Comparative Analysis.","authors":"Yujin Lee, YoungRyeol Lee, ChulEung Kim, Jin-Hee Han, MyungJe Sung, Jina Jung, KiWon Song, Hyemi Park","doi":"10.3346/jkms.2026.41.e212","DOIUrl":"10.3346/jkms.2026.41.e212","url":null,"abstract":"<p><strong>Background: </strong>Public concern regarding homicides committed by individuals with schizophrenia has intensified in recent years. Although the overall crime rate in this population is not significantly higher than that of the general population, certain subgroups may present an elevated homicide risk. Identifying associated risk factors and distinguishing between impulsive and premeditated violence are crucial for developing effective forensic psychiatric assessment and prevention strategies.</p><p><strong>Methods: </strong>Medical records of patients with schizophrenia admitted to the National Forensic Hospital in Korea from 2020 to 2024 were retrospectively reviewed. Patients were classified into the homicide group (HG; n = 55) and non-homicide violent group (VG; n = 49). Demographic and clinical data, trauma history, treatment adherence, cognitive function (Korean Wechsler Adult Intelligence Scale), symptom severity (Positive and Negative Syndrome Scale [PANSS]), personality traits (Minnesota Multiphasic Personality Inventory [MMPI] and Personality Assessment Inventory [PAI]), and crime-related characteristics were extracted from psychiatric evaluations, inpatient records, and psychological test results. The χ² tests, <i>t</i>-tests, and Mann-Whitney <i>U</i> tests were used for statistical analysis.</p><p><strong>Results: </strong>Most violent acts occurred during periods of treatment discontinuation and were most commonly driven by persecutory delusions and hallucinations. Both groups frequently experienced limited social support and a history of childhood trauma or adult victimization. The HG was more likely to commit premeditated, organized crimes using sharp weapons against family members in private settings. Conversely, the VG tended to exhibit impulsive violence in public settings, often against strangers and without weapons. Persecutory delusions predominated in both groups, whereas grandiose delusions were more prevalent in the VG. The HG had higher MMPI Psychopathic Deviate and Psychasthenia subscale and PAI suicidal ideation scale scores, whereas the VG showed higher PANSS positive symptom scores. The VG also demonstrated more frequent violent incidents and rehospitalizations.</p><p><strong>Conclusion: </strong>Although psychotic symptoms underpinned violence in both groups, the HG showed antisocial traits, suicidal tendencies, and premeditated violence. Conversely, the VG exhibited more severe positive symptoms, grandiosity, and recurrent impulsive violence. These findings highlight the importance of comprehensive violence risk assessments in schizophrenia that incorporate symptomatology, personality pathologies, and violence typologies.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e212"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503056/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nationwide Analysis of Surgery and Catheterization Services for Congenital Heart Disease: Regional Disparities and Patient Migration in Korea.","authors":"Soo In Jeong, Hae-Rim Kim, Hyungtae Kim","doi":"10.3346/jkms.2026.41.e120","DOIUrl":"10.3346/jkms.2026.41.e120","url":null,"abstract":"<p><strong>Background: </strong>Despite advancements in congenital heart disease (CHD) outcomes in Korea, equitable access to pediatric cardiac care is challenged by significant regional disparities. This study aimed to evaluate nationwide patterns of CHD surgeries and catheterizations, focusing on regional access and patient migration factors.</p><p><strong>Methods: </strong>Using the National Health Insurance Sharing Service database, we conducted procedure-level, cross-sectional analyses of CHD patients (aged 0-19 years) using datasets from 2012, 2017, and 2022. We measured volumes, regional utilization ratio (RUR), and migration. RUR was defined as the number of procedures performed within a region divided by the procedures received by its residents. Multivariable logistic regression identified determinants of out-of-region care.</p><p><strong>Results: </strong>We analyzed 6,438 surgeries and 11,276 catheterizations. Surgical volume declined but the proportion of complex surgeries rose from 42.9% in 2012 to 54.1% in 2022. Surgical care was highly centralized in Seoul (RUR > 4.0 in 2022). Out-of-region surgery was more likely for complex procedures, cyanotic CHD, and age 1-5 years; 53.8% of surgeries were performed outside the residential regions. Catheterization volume increased nationally with rising regional RUR. The proportion of inter-regional catheterizations decreased from 29.2% in 2012 to 15.2% in 2022. However, migration remained more frequent among infants, those with cyanotic CHD, higher socioeconomic status, and cardiac disability registration.</p><p><strong>Conclusion: </strong>Regional disparity persists in Korean pediatric CHD care, with marked centralization of surgery in Seoul. Regional access to catheterization has improved, yet high-risk subgroups (infants and cyanotic CHD) continue to receive out-of-region care. Strategic investment in regional infrastructure and workforce development, combined with efforts to shift patient perceptions and strengthen institutional collaborations, are essential to ensuring timely, equitable, and high-quality CHD care for all children across Korea.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e120"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503053/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-World Outcomes of Tisagenlecleucel Versus Standard-of-Care Salvage Chemotherapy in Relapsed or Refractory Diffuse Large B-Cell Lymphoma: A Propensity Score-Matched Analysis From Korea.","authors":"Seonggyu Byeon, Suein Choi, Seungpil Jung, Ka Young Kim, Dae Hun Kwag, Gi-June Min, Jung Yeon Lee, Sung-Soo Park, Silvia Park, Jae-Ho Yoon, Sung-Eun Lee, Byung-Sik Cho, Yoo-Jin Kim, Chang-Ki Min, Hee-Je Kim, Seok-Goo Cho, Young-Woo Jeon, Ki-Seong Eom","doi":"10.3346/jkms.2026.41.e214","DOIUrl":"10.3346/jkms.2026.41.e214","url":null,"abstract":"<p><strong>Background: </strong>Tisagenlecleucel, a CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy, has shown durable efficacy in relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, comparative real-world data against standard-of-care (SOC) therapies remain scarce in Asian populations.</p><p><strong>Methods: </strong>We performed a retrospective, propensity score-matched cohort study at two tertiary hospitals in Korea. Adult patients with R/R DLBCL treated in the third-line (3L) or later setting received either tisagenlecleucel (CAR-T cohort) or SOC salvage chemoimmunotherapy. Propensity score matching (1:1) was conducted using age, sex, line of therapy, International Prognostic Index, Eastern Cooperative Oncology Group status, and year of diagnosis. Outcomes included response rates, progression-free survival (PFS), overall survival (OS), and safety.</p><p><strong>Results: </strong>Among 178 eligible patients (CAR-T, n = 67; SOC, n = 111), 100 were matched (50 per group). The CAR-T cohort achieved a significantly higher overall response rate (68% vs. 28%) and complete response rate (60% vs. 22%). Median PFS was 4.8 months for CAR-T vs. 1.6 months for SOC (hazard ratio [HR], 0.49; <i>P</i> = 0.003), and median OS was 11.9 months vs. 3.3 months (HR, 0.51; <i>P</i> = 0.013). Subgroup analyses generally favored CAR-T across most clinical strata. CAR-T toxicities were manageable, with cytokine release syndrome (16%) and neurotoxicity (6%) observed, while SOC regimens were associated with higher chemotherapy-related cytopenias.</p><p><strong>Conclusion: </strong>In this real-world propensity score-matched comparison from Asia, tisagenlecleucel demonstrated superior survival and response outcomes compared with SOC salvage chemotherapy in Korean patients with R/R DLBCL, supporting its role as the standard of care in the ≥ 3L setting.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e214"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503052/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter to the Editor: Proton Pump Inhibitors and Depression: Implications for Perioperative Stress Ulcer Prophylaxis.","authors":"Xue-Lei Zhan","doi":"10.3346/jkms.2026.41.e331","DOIUrl":"10.3346/jkms.2026.41.e331","url":null,"abstract":"","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 33","pages":"e331"},"PeriodicalIF":3.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From \"When\" to \"Ready\": Preparing for Primary Colonoscopy in the Korean National Colorectal Cancer Screening Program.","authors":"Tae Hee Lee","doi":"10.3346/jkms.2026.41.e322","DOIUrl":"https://doi.org/10.3346/jkms.2026.41.e322","url":null,"abstract":"","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 32","pages":"e322"},"PeriodicalIF":3.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481803/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 10-Year Experience of Teledermatology in a Korean Correctional Facility: A Retrospective Observational Study.","authors":"Seung Hee Jang, Sang Woo Ahn, Seong Min Hong, So Hee Park, So Young Jung, Jung Eun Seol, Hyojin Kim","doi":"10.3346/jkms.2026.41.e222","DOIUrl":"10.3346/jkms.2026.41.e222","url":null,"abstract":"<p><strong>Background: </strong>Teledermatology offers a potential solution for providing dermatologic care in correctional facilities, where access to specialists is often limited.</p><p><strong>Methods: </strong>We conducted a retrospective observational study of all live-interactive teledermatology consultations between the dermatology department of Busan Paik Hospital and Busan Correctional Facility from 2013 to 2023. Data were extracted from electronic medical records and included demographics, diagnostic categories, individual diagnoses, treatment outcomes, and follow-up rates.</p><p><strong>Results: </strong>A total of 1,236 incarcerated patients (mean age, 38.5 years; 85.4% male, 14.6% female) were included. Infectious skin diseases (41.5%), eczematous conditions (24.4%), and diseases of skin appendages (17.2%) were the most frequent diagnostic categories. The most common diagnoses were dermatomycosis (13.8%), folliculitis (13.5%), acne (12.5%), contact dermatitis (10.1%), and scabies (8.7%). Of the patients, 453 (40.8%) received follow-up evaluations; among them, 320 (59.3%) demonstrated clinical improvement. Improvement rates were highest in infectious diseases (65.9%), compared to eczematous (53.7%) and appendage-related (53.8%) conditions. Notably, scabies incidence markedly declined after 2022, coinciding with increased preventive topical permethrin use by on-site clinicians.</p><p><strong>Conclusion: </strong>This 10-year experience demonstrates that teledermatology is a feasible, effective tool for delivering specialist care in correctional settings, with meaningful clinical improvements. Early detection and preventive strategies may further reduce disease burden, especially for conditions such as scabies. Our findings support teledermatology as a valuable approach to address health care disparities in underserved, closed populations.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 32","pages":"e222"},"PeriodicalIF":3.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481809/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twin Birth Weight Chart Comparisons in Korea.","authors":"Hyeseon Kim, So Yoon Ahn, Sang Ah Chi, Soo Jeong Choo, Seung Hyun Kim, Na Hyun Lee, Misun Yang, Se In Sung, Kyunga Kim, Yun Sil Chang","doi":"10.3346/jkms.2026.41.e215","DOIUrl":"https://doi.org/10.3346/jkms.2026.41.e215","url":null,"abstract":"<p><strong>Background: </strong>Birth weight deviations from gestational age-specific standards affect neonatal outcomes. While singleton references are established, their applicability to twins is debated. With the increasing incidence of twin and preterm births, twin-specific growth standards remain limited in Korea. This study systematically analyzed twin growth trajectories, considering sex, mode of conception, and chorionicity, to establish accurate references.</p><p><strong>Methods: </strong>This study analyzed data from the Korean Neonatal Network (2013-2020; ≤ 28 weeks, twins: 2,789; singletons: 6,171) and Samsung Medical Center (1995-2023; 22-37 weeks; twins: 4,201; singletons: 10,883). Birth weight distributions were compared between twins and singletons, and among subgroups defined by sex, mode of conception, and chorionicity. Smoothed percentile curves were constructed using a generalized additive model for location, scale, and shape, and validated by worm plots and bootstrap analysis.</p><p><strong>Results: </strong>At 32 weeks of gestation, the median birth weight of twins was 1,750 g (interquartile range, 1,600-1,950), and that of singletons was 2,050 g (1,850-2,250) (<i>P</i> < 0.001). Male twins had a higher median birth weight than females (1,800 g [1,650-1,980] vs. 1,700 g [1,550-1,880]). Twins conceived by in vitro fertilization had a lower median birth weight than those conceived spontaneously (2,173 g [1,940-2,390] vs. 2,340 g [2,100-2,560]; <i>P</i> < 0.001) in the unadjusted analysis; however, this difference diminished and was not statistically significant in subgroup analyses by gestational age, sex, or chorionicity. The growth model demonstrated good fit to the data across gestational ages.</p><p><strong>Conclusion: </strong>Subgroup analyses by chorionicity, sex, and mode of conception did not reveal statistically significant differences. The twin-specific birth weight charts demonstrated a good model fit and internal consistency within the study population. These findings support their potential utility as reference standards for the clinical evaluation of twin growth in Korea. Further validation in larger and more diverse cohorts is warranted to confirm their generalizability.</p>","PeriodicalId":16249,"journal":{"name":"Journal of Korean Medical Science","volume":"41 32","pages":"e215"},"PeriodicalIF":3.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}