Objective: This study aimed to compare aneuploidy rates and clinical outcomes between trophectoderm biopsy at fresh blastocyst (biopsy-fresh) followed by vitrification and biopsy at vitrified-warmed blastocyst (biopsy-vitri) followed by next day transfer (without re-vitrification). Methods: This retrospective study included 844 patients undergoing 844 cycles conducted from August 2019 to December 2023. Preimplantation genetic testing for aneuploidy (PGT-A) was performed via trophectoderm biopsy using array comparative genomic hybridization or next-generation sequencing for comprehensive 24-chromosome screening. Patients were divided into two groups based on the blastocyst status at the time of biopsy: the biopsy-fresh group (531 patients) and the biopsy-vitri group (313 patients). Results: The clinical pregnancy rate was significantly higher in the biopsy-fresh group compared to the biopsy-vitri group (58.7% vs. 45.6%; odds ratio [OR], 1.695; 95% confidence interval [CI], 1.215 to 2.364; p=0.002). Furthermore, the biopsy-fresh group showed higher implantation rates (45.6% vs. 32.1%; OR, 1.767; 95% CI, 1.274 to 2.451; p=0.002), ongoing pregnancy or live birth rates per cycle (48.0% vs. 35.8%; OR, 1.652; 95% CI, 1.177 to 2.319; p=0.004), and rates of good-quality blastocysts (57.1% vs. 32.1%, p<0.001) compared with the biopsy-vitri group. Miscarriage rates did not differ significantly between the groups (18.2% vs. 21.4%; OR, 0.818; 95% CI, 0.457 to 1.465; p=0.501). Conclusion Biopsy at fresh blastocyst demonstrated superior clinical outcomes compared with biopsy at vitrified-warmed blastocyst, likely due to better embryo quality. Both biopsy at fresh blastocyst and vitrified-warmed blastocyst remain viable options for PGT-A, with biopsy at vitrified-warmed blastocyst serving as a practical alternative. Embryo quality and euploid status continue to be critical considerations for embryo transfer selection.

Purpose: The goniometer, the gold standard for range of motion (ROM) assessment, has significant limitations including physical contact requirements and high interrater variability. While markerless motion capture using deep learning (e.g., Sports2D) offers a noncontact alternative, its clinical reliability remains unestablished. This study evaluated Sports2D's reliability for ROM measurement using smartphone cameras compared to conventional goniometry. Methods: Fifty healthy adults (25 males, 25 females; mean age, 22.42±2.58 years) participated. Ten joint ROM types (17 total measurements including left/right) were measured using both traditional goniometry (by an experienced clinician) and Sports2D (smartphone camera at 3 m distance). Reliability and agreement were analyzed using concordance correlation coefficient (CCC), Pearson correlation, and Bland-Altman plots. Results: Sports2D demonstrated very high reliability for elbow flexion (CCC, 0.906−0.955), neck extension (CCC, 0.928), and right hip flexion (CCC, 0.920). Good reliability (CCC, ≥ 0.8) was observed for neck flexion, left knee flexion, and trunk flexion. However, all ankle measurements showed clinically unacceptable reliability (CCC, ＜ 0.3), including dorsiflexion (CCC, 0.072−0.099) and plantarflexion (CCC, 0.174–0.211). Bland-Altman plots confirmed proportional bias for ankle measurements, particularly at smaller angles. Conclusion Sports2D is a reliable noncontact tool for measuring ROM in specific joints including elbow, neck, knee, hip, and trunk. However, it is unreliable for ankle joint assessment due to significant measurement discrepancies. These findings highlight the need for selective clinical application of markerless motion capture based on joint-specific validation.

Purpose: The current drain tubes for preventing surgically biliary anastomotic stricture are not naturally and easily removed. If a drain tube using biodegradable material is easily available and the degradation time of the tube is well controlled, surgical anastomotic stricture and fibrosis could be prevented. The aim of this animal study was to evaluate the preventive effect of novel biodegradable stents (BS) on biliary stricture and fibrosis after duct-to-duct (DD) biliary anastomosis. Methods: Ten mini-pigs were allocated to the control group (n = 5) and or the stent group (n = 5). The common bile duct was exposed through surgical laparotomy and then resected transversely. In the stent group, a 4-mm or 6-mm polydioxanone/ magnesium sheath-core BS was inserted according to the width of the bile duct, followed by DD biliary anastomosis. In the control group, DD biliary anastomosis was performed without BS insertion. Results: In the stent group, stents were observed without deformity for up to 4 weeks in all animals. Eight weeks later, histopathologic examination revealed that the common bile duct of the anastomosis site was relatively narrower in circumference in the control group compared to the stent group. The degree of fibrosis in the control group was more marked than in the stent group (3.84 mm vs. 0.68 mm, respectively; P < 0.05). Conclusion Our study showed that novel BS maintained their original shape and radial force for an adequate time and then disappeared without adverse events. The BS could prevent postoperative complications and strictures after DD biliary anastomosis.

PURPOSE: The purpose of the study was to examine the recording accuracy of faculty observers and standardized patients (SPs) on a clinical performance examination (CPX). METHODS: This was a cross-sectional study of a fourth-year medical students' CPX that was held at a medical school in Seoul, Korea. The CPX consisted of 4 cases and was administered to 118 examinees, with the participation of 52 SP and 45 faculty observers. For the study we chose 15 examinees per case, and analyzed 60 student-SP encounters in total. To determine the recording accuracy level, 2 SP trainers developed an answer key for each encounter. First, we computed agreement rates (P) and kappa coefficient (K) values between the answer key-SPs and the answer key-faculty observers. Secondly, we analyzed variance (ANOVA) with repeated measures to determine whether the mean percentage of the correct checklist score differed as a function of the rater, the case, or the interaction between both factors. RESULTS: Mean P rates ranged from 0.72 to 0.86, while mean K values varied from 0.39 to 0.59. The SP checklist accuracy was higher than that of faculty observersat the level of item comparison. Results from ANOVA showed that there was no significant difference between the percentage of correct scores by the answer key, faculty observers and SPs. There was no significant interaction between rater and case factors. CONCLUSION: Acceptable levels of recording accuracy were obtained in both rater groups. SP raters can replace faculty raters in a large-scale CPX with thorough preparation.
Checklist ; Clinical Competence ; Cross-Sectional Studies ; Education, Medical, Undergraduate ; Educational Measurement ; Humans ; Korea ; Observer Variation ; Schools, Medical

PURPOSE: The purpose of the study was to develop and validate a questionnaire to evaluate medical students' knowledge of, attitude towards and practice of evidence-based medicine (EBM). METHODS: The participants of the study were 418 medical students enrolled in the Kyung Hee University School of Medicine in Seoul, Korea. To examine construct validity of the questionnaire, an exploratory factor analysis (EFA) was performed with 118 participants; a confirmatory factor analysis (CFA) was conducted with the remaining 281 participants. We developed 41 items with a 4-point Likert scale. An EFA was performed to verify the emergence of four dimensions of EBM competencies. The principal axis factoring method and the direct oblimin rotation method were used. To confirm construct validity, a CFA was conducted with the remaining 281 participants. To evaluate model fitness, root mean square error of approximation (RMSEA) and comparative fit index (CFI) were used as fit indices. We conducted ANOVA with Scheffe as discriminant validation, and calculated Cronbach's alpha of 4 subscales as reliability checkup. RESULTS: After refinement procedure, factor analysis of the 32 items in therevised questionnaire yielded 4 factors. The Scree plot supported a 4 factor solution explaining 53.5% of the variance. The 4 components derived were: factor 1_knowledge on EBM (11 items; Cronbach's alpha=0.92); factor 2_ pursuit towards EBM (10; 0.88); factor 3_reluctance on EBM (7; 0.78); factor 4_practice of EBM (4; 0.75). The questionnaire could discriminate competence differences among 1-3 yr students. Satisfactory Cronbach's alpha scores were noted for each factor as well. CONCLUSION: The EBM competency questionnaire was validated.
Axis, Cervical Vertebra ; Education, Medical, Undergraduate ; Educational Measurement ; Evidence-Based Medicine ; Humans ; Korea ; Mental Competency ; Students, Medical ; Surveys and Questionnaires

PURPOSE: The purpose of the study was to develop and validate a questionnaire to evaluate medical students' knowledge of, attitude towards and practice of evidence-based medicine (EBM). METHODS: The participants of the study were 418 medical students enrolled in the Kyung Hee University School of Medicine in Seoul, Korea. To examine construct validity of the questionnaire, an exploratory factor analysis (EFA) was performed with 118 participants; a confirmatory factor analysis (CFA) was conducted with the remaining 281 participants. We developed 41 items with a 4-point Likert scale. An EFA was performed to verify the emergence of four dimensions of EBM competencies. The principal axis factoring method and the direct oblimin rotation method were used. To confirm construct validity, a CFA was conducted with the remaining 281 participants. To evaluate model fitness, root mean square error of approximation (RMSEA) and comparative fit index (CFI) were used as fit indices. We conducted ANOVA with Scheffe as discriminant validation, and calculated Cronbach's alpha of 4 subscales as reliability checkup. RESULTS: After refinement procedure, factor analysis of the 32 items in therevised questionnaire yielded 4 factors. The Scree plot supported a 4 factor solution explaining 53.5% of the variance. The 4 components derived were: factor 1_knowledge on EBM (11 items; Cronbach's alpha=0.92); factor 2_ pursuit towards EBM (10; 0.88); factor 3_reluctance on EBM (7; 0.78); factor 4_practice of EBM (4; 0.75). The questionnaire could discriminate competence differences among 1-3 yr students. Satisfactory Cronbach's alpha scores were noted for each factor as well. CONCLUSION: The EBM competency questionnaire was validated.
Axis, Cervical Vertebra ; Education, Medical, Undergraduate ; Educational Measurement ; Evidence-Based Medicine ; Humans ; Korea ; Mental Competency ; Students, Medical ; Surveys and Questionnaires

PURPOSE: The "standardization" of standardized patients (SP) is one of the most crucial factors for a successful clinical performance examination (CPX). This study aimed to examine the inter-rater reliability among SPs who portrayed the same case during a CPX. METHODS: The context was a CPX conducted under the supervision of CPX Seoul-Gyeonggi Consortium in K medical school in August 2007. K medical school ran 12 stations consisting of duplicated sets of 6 cases. In total, thirty SPs participated with 5 SPs acting each of the 6 cases. The SPs evaluated the student's performances in addition to portraying the cases. ANCOVA (analysis of covariance) was used to compare scores rated by the different SPs. The dependent variables were the case scores and the 4 subcomponent (history taking, physical examination, Clinical courtesy, and Patient-physician interaction) scores for each case; the independent variable was the SPs; and the covariate was the CPX total score. RESULTS: The Headache and Cough stations showed an acceptable level of reliability. Otherwise, Weight Loss and Facial Flushing failed to show consistent scores in all 4 subcomponents. Diarrhea and Lt. hemiparesis showed partial consistency. In terms of the subcomponents, the physical exam scores were most consistent and the patient-physician interaction scores were most inconsistent. CONCLUSION: This study tested the level of "standardization" of one set of CPX cases with mixed results. The authors hope that our results will contribute to quality assurance of CPX.
Cough ; Diarrhea ; Flushing ; Headache ; Humans ; Organization and Administration ; Paresis ; Physical Examination ; Schools, Medical ; Weight Loss

PURPOSE: This study aims to explore which coping strategies medical students use more often, and how coping styles account for medical students' subjective well-being. METHODS: Subjects included 249 medical students from undergraduate and Graduate Entry Programme of a medical school in Seoul, Korea. Coping style was measured using the Ways of Coping Checklist. Subjective well-being was measured with Positive/Negative Affect Scale and Satisfaction with Life Scale. Analysis of Variance(ANOVA) was used to compare four coping strategies, and stepwise multiple regression was used to analyze the accountability of each of the coping strategy for subjective well-being. RESULTS: Medical students used avoidance and problem-focused coping strategy more often than they used emotion-focused coping strategy and seeking social support. Graduate Entry Programme students used avoidance less often and seeking social support more often than undergraduate students. Among subscales of subjective well-being, positive affect can be accounted for by problem-focused coping and seeking social support, and negative affect can be accounted for by problem-focused coping and avoidance. Life satisfaction can be accounted for by problem-focused coping as well. CONCLUSION: The results of this study showed that medical students had high adaptability as well as strong anxiety toward stressful situations in medical school. Moreover, three among the four coping strategies accounted for medical students' subjective well-being. These findings should be considered as a baseline for future research looking into additional variables affecting medical students' well-being.
Anxiety ; Checklist ; Education, Medical ; Humans ; Korea ; Schools, Medical ; Seoul ; Social Responsibility ; Students, Medical*