1.Improving appendix cancer prediction with SHAP-based feature engineering for machine learning models: a prediction study
The Ewha Medical Journal 2025;48(2):e31-
Purpose:
This study aimed to leverage Shapley additive explanation (SHAP)-based feature engineering to predict appendix cancer. Traditional models often lack transparency, hindering clinical adoption. We propose a framework that integrates SHAP for feature selection, construction, and weighting to enhance accuracy and clinical relevance.
Methods:
Data from the Kaggle Appendix Cancer Prediction dataset (260,000 samples, 21 features) were used in this prediction study conducted from January through March 2025, in accordance with TRIPOD-AI guidelines. Preprocessing involved label encoding, SMOTE (synthetic minority over-sampling technique) to address class imbalance, and an 80:20 train-test split. Baseline models (random forest, XGBoost, LightGBM) were compared; LightGBM was selected for its superior performance (accuracy=0.8794). SHAP analysis identified key features and guided 3 engineering steps: selection of the top 15 features, construction of interaction-based features (e.g., chronic severity), and feature weighting based on SHAP values. Performance was evaluated using accuracy, precision, recall, and F1-score.
Results:
Four LightGBM model configurations were evaluated: baseline (accuracy=0.8794, F1-score=0.8691), feature selection (accuracy=0.8968, F1-score=0.8860), feature construction (accuracy=0.8980, F1-score=0.8872), and feature weighting (accuracy=0.8986, F1-score=0.8877). SHAP-based engineering yielded performance improvements, with feature weighting achieving the highest precision (0.9940). Key features (e.g., red blood cell count and chronic severity) contributed to predictions while maintaining interpretability.
Conclusion
The SHAP-based framework substantially improved the accuracy and transparency of appendix cancer predictions using LightGBM (F1-score=0.8877). This approach bridges the gap between predictive power and clinical interpretability, offering a scalable model for rare disease prediction. Future validation with real-world data is recommended to ensure generalizability.
2.Environmental disease monitoring by regional Environmental Health Centers in Korea: a narrative review
Myung-Sook PARK ; Hwan-Cheol KIM ; Woo Jin KIM ; Yun-Chul HONG ; Won-Jun CHOI ; Seock-Yeon HWANG ; Jiho LEE ; Young-Seoub HONG ; Yong-Dae KIM ; Seong-Chul HONG ; Joo Hyun SUNG ; Inchul JEONG ; Kwan LEE ; Won-Ju PARK ; Hyun-Joo BAE ; Seong-Yong YOON ; Cheolmin LEE ; Kyoung Sook JEONG ; Sanghyuk BAE ; Jinhee CHOI ; Ho-Hyun KIM
The Ewha Medical Journal 2025;48(1):e3-
This study explores the development, roles, and key initiatives of the Regional Environmental Health Centers in Korea, detailing their evolution through four distinct phases and their impact on environmental health policy and local governance. It chronicles the establishment and transformation of these centers from their inception in May 2007, through four developmental stages. Originally named Environmental Disease Research Centers, they were subsequently renamed Environmental Health Centers following legislative changes. The analysis includes the expansion in the number of centers, the transfer of responsibilities to local governments, and the launch of significant projects such as the Korean Children’s Environmental Health Study (Ko-CHENS ). During the initial phase (May 2007–February 2009), the 10 centers concentrated on research-driven activities, shifting from a media-centered to a receptor-centered approach. In the second phase, prompted by the enactment of the Environmental Health Act, six additional centers were established, broadening their scope to address national environmental health issues. The third phase introduced Ko-CHENS, a 20-year national cohort project designed to influence environmental health policy by integrating research findings into policy frameworks. The fourth phase marked a decentralization of authority, empowering local governments and redefining the centers' roles to focus on regional environmental health challenges. The Regional Environmental Health Centers have significantly evolved and now play a crucial role in addressing local environmental health issues and supporting local government policies. Their capacity to adapt and respond to region-specific challenges is essential for the effective implementation of environmental health policies, reflecting geographical, socioeconomic, and demographic differences.
3.How to Achieve Diversity, Equity, and Inclusion in The Korean Society of Gastroenterology?
Nayoung KIM ; Kwangwoo NAM ; Ki-Nam SHIM ; Hyo Jung KIM ; Su Youn NAM ; Sae Kyung JOO ; Seun Ja PARK ; Yonghoon CHOI ; Yoon Ju JUNG ; Yong Sung KIM ; Ja Kyung KIM ; Seon Mee PARK
The Korean Journal of Gastroenterology 2025;85(1):22-30
With the increasing emphasis on diversity, equity, and inclusion (DEI) in organizations and institutions, academic societies in gastroenterology and hepatology are beginning to take actionable steps toward achieving DEI. The successful implementation of DEI initiatives leads to excellence in the field, improved patient outcomes, particularly in areas where health disparities are prevalent, and advances in the gastrointestinal discipline. Such implementation also results in a workforce that better reflects the growing diversity of the population. This review defines DEI and introduces the DEI policies and strategies adopted by the academic societies of gastroenterology in other countries. This paper proposes strategies to integrate DEI better into the Korean Society of Gastroenterology, emphasizing the importance of embedding DEI into the culture and strategic framework. The key strategies include establishing a DEI committee, setting clear targets, and conducting formal assessments to measure DEI progress. This study focused on enhancing workforce diversity, particularly among women and young doctors, and advocates for the need to support their academic development through male allyship and the promotion of equitable and inclusive academic cultures.
4.Detection of Clarithromycin Resistance in Helicobacter pylori Using the AllplexTM H. pylori & ClariR Assay and the Ezplex® HP-CLA Real-Time PCR Kit
Tae-Woo KIM ; Won Seok LEE ; Dong Jin YOON ; Ilsoo KIM ; Joon Sung KIM
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2025;25(1):42-47
Objectives:
The success of Helicobacter pylori eradication using clarithromycin-based triple therapy relies on the bacteria being sensitive to clarithromycin. This study evaluated the diagnostic performance of two frequently used polymerase chain reaction (PCR) methods (AllplexTM H. pylori & ClariR Assay [Seegene] and Ezplex® HP-CLA Real-time PCR [SML Genetree]) to detect H. pylori infection and identify point mutations associated with clarithromycin resistance.
Methods:
Patients who underwent esophagogastroduodenoscopy between August 2023 and April 2024 at Incheon St. Mary’s Hospital were enrolled in this study. The diagnostic performance of the Allplex method was evaluated against the rapid urease test (RUT), culture, and Ezplex HP-CLA methods. Point mutation detection using the Allplex and Ezplex methods was compared with the results of gene sequencing. The rates of H. pylori eradication following Ezplex-based tailored therapy were also analyzed.
Results:
Eighty-seven gastric biopsy specimens were analyzed. For diagnosing H. pylori infections, Allplex demonstrated kappa values of 0.670 compared with RUT, 0.468 compared with culture, and 0.880 compared with Ezplex. Among the 87 bacterial isolates subjected to gene sequencing to detect clarithromycin resistance-associated point mutations, the Allplex and Ezplex methods demonstrated 74 and 76 concordant results, respectively. The H. pylori eradication rate using Ezplex-based tailored therapy was 90.7%.
Conclusions
This study demonstrated that both the Allplex and Ezplex methods are helpful for diagnosing H. pylori infections and detecting clarithromycin resistance. Furthermore, the Ezplex method was clinically effective for guiding tailored therapy to yield successful H. pylori eradication.
5.Predictive value and optimal cut-off level of high-sensitivity troponin T in patients with acute pulmonary embolism
Moojun KIM ; Chang-Ok SEO ; Yong-Lee KIM ; Hangyul KIM ; Hye Ree KIM ; Yun Ho CHO ; Jeong Yoon JANG ; Jong-Hwa AHN ; Min Gyu KANG ; Kyehwan KIM ; Jin-Sin KOH ; Seok-Jae HWANG ; Jin Yong HWANG ; Jeong Rang PARK
The Korean Journal of Internal Medicine 2025;40(1):65-77
Background/Aims:
Elevated troponin levels predict in-hospital mortality and influence decisions regarding thrombolytic therapy in patients with acute pulmonary embolism (PE). However, the usefulness of high-sensitivity troponin T (hsTnT) regarding PE remains uncertain. We aimed to establish the optimal cut-off level and compare its performance for precise risk stratification.
Methods:
374 patients diagnosed with acute PE were reviewed. PE-related adverse outcomes, a composite of PE-related deaths, cardiopulmonary resuscitation incidents, systolic blood pressure < 90 mmHg, and all-cause mortality within 30 days were evaluated. The optimal hsTnT cut-off for all-cause mortality, and the net reclassification index (NRI) was used to assess the incremental value in risk stratification.
Results:
Among 343 normotensive patients, 17 (5.0%) experienced all-cause mortality, while 40 (10.7%) had PE-related adverse outcomes. An optimal hsTnT cut-off value of 60 ng/L for all-cause mortality (AUC 0.74, 95% CI 0.61–0.85, p < 0.001) was identified, which was significantly associated with PE-related adverse outcomes (OR 4.07, 95% CI 2.06–8.06, p < 0.001). Patients with hsTnT ≥ 60 ng/L were older, hypotensive, had higher creatinine levels, and right ventricular dysfunction signs. Combining hsTnT ≥ 60 ng/L with simplified pulmonary embolism severity index ≥1 provided additional prognostic information. Reclassification analysis showed a significant shift in risk categories, with an NRI of 1.016 ± 0.201 (p < 0.001).
Conclusions
We refined troponin’s predictive value in patients with acute PE, proposing a new cut-off value of hsTnT ≥ 60 ng/L. Validation through large-scale studies is essential to offer clinically useful guidance for managing patient population.
6.The characteristics of Korean elderly multiple myeloma patients aged 80 years or over
Sang Hwan LEE ; Hee-Jeong CHO ; Joon Ho MOON ; Ji Yoon JUNG ; Min Kyoung KIM ; Mi Hwa HEO ; Young Rok DO ; Yunhwi HWANG ; Sung Hwa BAE
The Korean Journal of Internal Medicine 2025;40(1):115-123
Background/Aims:
Multiple myeloma (MM) predominantly affects elderly individuals, but studies on older patients with MM are limited. The clinical characteristics and survival outcomes of patients with MM aged 80 years or over were retrospectively analyzed.
Methods:
This retrospective multicenter study was conducted to investigate the clinical characteristics, treatment patterns, and survival outcomes of patients aged 80 years or over who were newly diagnosed with MM at five academic hospitals in Daegu, Korea, between 2010 and 2019.
Results:
A total of 127 patients with a median age of 83 years (range, 80–93 yr) were enrolled: 52 (40.9%) with Eastern Cooperative Oncology Group Performance Status (ECOG PS) > 2, 84 (66.1%) with International Staging System (ISS) stage III disease, and 93 (73.2%) with a Charlson comorbidity index (CCI) > 4. Chemotherapy was administered to 86 patients (67.7%). The median overall survival was 9.3 months. Overall survival was significantly associated with ECOG PS > 2 (HR 2.26, 95% CI 1.43–3.59), ISS stage III (HR 1.99, 95% CI 1.18–3.34), and chemotherapy (HR 0.34, 95% CI 0.21–0.55). There was no statistically significant difference in event-free survival according to the type of anti-myeloma chemotherapy administered. The early mortality (EM) rate was 28.3%.
Conclusions
Even in patients with MM aged 80 years or over, chemotherapy can result in better survival outcomes than supportive care. Patients aged ≥ 80 years should not be excluded from chemotherapy based on age alone. However, reducing EM in elderly patients with newly diagnosed MM remains challenging.
7.Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea
Ki Jin KIM ; Su-Bin SONG ; Jung-Bin PARK ; June Hwa BAE ; Ji Eun BAEK ; Ga Hee KIM ; Min-Jun KIM ; Seung Wook HONG ; Sung Wook HWANG ; Dong-Hoon YANG ; Byong Duk YE ; Jeong-Sik BYEON ; Seung-Jae MYUNG ; Suk-Kyun YANG ; Chang Sik YU ; Yong-Sik YOON ; Jong-Lyul LEE ; Min Hyun KIM ; Ho-Su LEE ; Sang Hyoung PARK
The Korean Journal of Internal Medicine 2025;40(2):243-250
Background/Aims:
Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea.
Methods:
This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans.
Results:
A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR.
Conclusions
Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.
8.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
9.Preliminary study on change in the upper airway dimension in growing patients with Pierre-Robin sequence
Su-Ji YOON ; Il-Hyung YANG ; Su-Jung KIM ; Seung-Hak BAEK
The Korean Journal of Orthodontics 2025;55(2):105-119
Objective:
This study aimed to evaluate the changes in upper airway (UA) dimensions in growing patients with Pierre-Robin sequence (PRS).
Methods:
The subjects were 23 PRS patients who had not undergone growth modification therapy or surgical intervention. Their lateral cephalograms were obtained longitudinally at mean ages of 8.81 (T0) and 14.05 (T1). Patients were categorized based on their SNB value at T0 (Criteria: –2 SD): Group-1 (very retrusive mandible, n = 13) and Group-2 (moderately retrusive mandible, n = 10). Skeletal and UA variables at T0 and T1, as well as ∆T0-T1, were statistically analyzed.
Results:
At T0, Group-1 exhibited more retrusive maxilla and mandible (SNA, P < 0.01; SNB, P < 0.001), a more hyperdivergent pattern (facial height ratio, P < 0.05), and a more posteriorly positioned hyoid bone (H-PTV, P < 0.05), while Group-1 showed larger UA spaces (superior pharyngeal airway space [SPAS] and inferior pharyngeal airway space, all P < 0.05) than Group 2, which might indicate the existence of a compensatory response to maintain the UA patency.At T1, Group-1 maintained significantly retrusive maxilla and mandible (SNA and SNB, all P < 0.01), exhibited a less anteriorly positioned tongue (TT-PTV, P < 0.05), and displayed a more obtuse soft palate angle (SPA, P < 0.05) than Group-2.Between T0 and T1, Group-1 demonstrated significant increases in the hyoid symphysis distance (∆H-RGN, P < 0.001), tongue length (∆TGL, P < 0.01), and pharyngeal UA spaces (∆SPAS and ∆PNS-ad2, all P < 0.001).
Conclusions
Even in growing PRS patients with severe mandibular retrusion, the UA dimensions increased due to forward growth of the mandible, repositioning of tongue and hyoid bone, and existence of compensatory mechanism.
10.Validation of the Korean version of defense and veterans pain rating scale for assessment of postoperative pain: a prospective observational cohort study
Seungeun CHOI ; Taeyup KIM ; Hae Kyeong YOO ; Sang-Youn PARK ; Soo-Hyuk YOON ; Ho-Jin LEE
The Korean Journal of Pain 2025;38(1):58-68
Background:
The defense and veterans pain rating scale (DVPRS) is a pain assessment tool combining a numerical rating scale (NRS) with descriptive words, colors, and facial expressions. This study aimed to validate the Korean version of the DVPRS (K-DVPRS) for postoperative pain assessment.
Methods:
This study included patients who underwent elective laparoscopic or robotic abdominal surgery. The original DVPRS was translated into Korean using a forward-backward method. Pain intensities at rest and during coughing were assessed at 24 and 48 hours postoperatively using the NRS and K-DVPRS, respectively. The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire was also used. The validity, reliability, and responsiveness of the K-DVPRS were evaluated.
Results:
Of the 174 patients screened, 150 were enrolled, and 148 completed the study. The K-DVPRS had strong convergent validity with the NRS at 24 and 48 hours postoperatively (ρ: 0.75 to 0.78, all P < 0.001). Construct validity was confirmed by significant differences in pain scores based on surgical extent and duration. The internal consistency was acceptable (Cronbach’s alpha: 0.77 and 0.85 at 24 and 48 hours, respectively), and test-retest reliability at 24 hours was excellent (intraclass correlation coefficient: 0.90 at rest and 0.95 during coughing).Responsiveness, measured by Cliff’s effect size, was high from preoperative to 24 hours postoperatively and moderate from 24 to 48 hours. At 48 hours, the K-DVPRS had stronger correlations with the EQ-5D-5L index and EQVAS than with the NRS.
Conclusions
The K-DVPRS is a valid, reliable, and responsive tool for assessing postoperative pain in Korean patients.

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