OBJECTIVES: The aim of this study was to develop a new prognostic classification for epithelial ovarian cancer (EOC) patients using gradient boosting (GB) and to compare the accuracy of the prognostic model with the conventional statistical method. METHODS: Information of EOC patients from Samsung Medical Center (training cohort, n=1,128) was analyzed to optimize the prognostic model using GB. The performance of the final model was externally validated with patient information from Asan Medical Center (validation cohort, n=229). The area under the curve (AUC) by the GB model was compared to that of the conventional Cox proportional hazard regression analysis (CoxPHR) model. RESULTS: In the training cohort, the AUC of the GB model for predicting second year overall survival (OS), with the highest target value, was 0.830 (95% confidence interval [CI]=0.802–0.853). In the validation cohort, the GB model also showed high AUC of 0.843 (95% CI=0.833–0.853). In comparison, the conventional CoxPHR method showed lower AUC (0.668 (95% CI=0.617–0.719) for the training cohort and 0.597 (95% CI=0.474–0.719) for the validation cohort) compared to GB. New classification according to survival probability scores of the GB model identified four distinct prognostic subgroups that showed more discriminately classified prediction than the International Federation of Gynecology and Obstetrics staging system. CONCLUSION: Our novel GB-guided classification accurately identified the prognostic subgroups of patients with EOC and showed higher accuracy than the conventional method. This approach would be useful for accurate estimation of individual outcomes of EOC patients.
Area Under Curve ; CA-125 Antigen ; Chungcheongnam-do ; Classification ; Cohort Studies ; Gynecology ; Humans ; Machine Learning ; Methods ; Obstetrics ; Ovarian Neoplasms ; Prognosis

OBJECTIVES: Several studies have delineated the relationship between hearing disturbances and the prevalence or characteristics of psychotic symptoms; however, most of those studies focused on psychiatric patients and not general inpatients. Delirium has a high incidence among general inpatients, and patients with delirium are easily affected by psychotic symptoms that lead to irritable behaviors. This study examined the relationship between hearing disturbance and psychotic symptoms among patients with delirium. METHODS: At the Asan Medical Center in Seoul, South Korea, this study examined 27 inpatients who had both delirium and hearing disturbances between January 1, 2009 and December 31, 2018, and 146 inpatients at the Asan Medical Center who had delirium but no hearing disturbances between July 1, 2018 and December 31, 2018. This study investigated whether the two groups showed differences in the prevalence and characteristics of delirium symptoms, particularly psychotic symptoms. In addition, the correlation between clinical characteristics of delirium and the recommended dosage of antipsychotics was analyzed in patients who had been diagnosed with delirium and had hearing disturbances. RESULTS: Compared to inpatients who only had delirium, those who had both delirium and hearing disturbances had a significantly higher prevalence of hallucination and delusion. CONCLUSION: The prevalence of psychotic symptoms, such as hallucination and delusion, was higher in patients who had both delirium and hearing disturbances, which is in line with the results from previous studies on psychiatric patients. Physicians should focus on improving communication with such patients by employing non-verbal communication methods.
Antipsychotic Agents ; Chungcheongnam-do ; Delirium ; Delusions ; Hallucinations ; Hearing ; Humans ; Incidence ; Inpatients ; Korea ; Prevalence ; Seoul

BACKGROUND: Rheumatoid factor (RF) is used as one of the diagnostic criteria for rheumatoid arthritis. The purpose of this study was to evaluate qualitative RF reagents used in clinical laboratories in Korea, and to provide basic data that can be used as a reference to improve the quality of RF testing. METHODS: We reviewed the proficiency testing results for RF from the Korean Association of External Quality Assessment Service (KEQAS) and College of American Pathologists. Moreover, we evaluated five commercially available RF qualitative reagents, including LabSlide RF (IVD Lab Co., Korea), ASAN RA Latex Reagents (Asan Pharmaceuticals Co., Korea), RaPET RF (Stanbio Laboratory, USA), RF Latex Test (Pulse Scientific Inc., Canada), and RF-100 (Teco Diagnostics, USA). Commercially available quality control materials, calibrators, and pooled sera were used in this study. The consistency of qualitative reagents and Kappa statistics were calculated based on the quantitative values of the quality control materials and the mixed sera. RESULTS: Up to 51.5% of high concentration samples were reported as negative in KEQAS. RF qualitative reagent test results were not consistent among reagent types. The consistency of the qualitative and quantitative test results was between 51% and 100%, and the kappa statistics varied depending on the reagent manufacturer. CONCLUSIONS: Measurement of RF qualitative reagents used in domestic clinical laboratories was not consistent with the quantitative values, and hence it is necessary to improve the consistency and verify the adequacy of the cut-off value.
Arthritis, Rheumatoid ; Chungcheongnam-do ; Indicators and Reagents ; Korea ; Latex ; Quality Control ; Rheumatoid Factor

BACKGROUND: Primary breast sarcoma (PBS) is rare, comprising approximately 1% of breast malignancies. Rhabdomyosarcoma (RMS) accounts for an extremely small proportion of PBSs, often leading to delayed histologic confirmation. METHODS: Upon reviewing Asan Medical Center’s pathology database between 2000 and 2018, 41 PBS cases were retrieved, including three cases of primary RMS of the breast. Their clinicopathological features were analyzed, and the literature related to PBS and primary RMS of the breast was reviewed. RESULTS: We identified three primary breast RMS cases from our institution database, comprising 7.3% of PBS: one case each of spindle cell/sclerosing RMS (ssRMS), alveolar RMS (aRMS), and embryonal RMS (eRMS). All cases involved adolescents or young adults (14, 16, and 25 years, respectively) who underwent mastectomy or radiotherapy and were confirmed using immunohistochemical testing for myogenin, desmin, and myogenic differentiation. The ssRMS patient experienced recurrence at the operation site 4 months post-surgery despite undergoing concurrent chemoradiotherapy. The aRMS patient had multiple metastases at diagnosis and showed FAX3-FOXO1 fusion transcripts; she died 22 months after the diagnosis. The eRMS patient had enlarged axillary lymph nodes; post-radiotherapy, the lesion recurred as multiple metastases to the bone and lung. She died 18 months post-diagnosis. CONCLUSIONS: Our experience on RMS cases suggests that spindle cell or small round cell malignancy in breasts of young female should raise suspicion for the possibility of primary or secondary RMS. To our knowledge, this is the second report of primary breast ssRMS and it may help clinicians who encounter this rare disease in the future.
Adolescent ; Arm ; Breast ; Chemoradiotherapy ; Chungcheongnam-do ; Desmin ; Diagnosis ; Female ; Humans ; Lung ; Lymph Nodes ; Mastectomy ; Myogenin ; Neoplasm Metastasis ; Pathology ; Radiotherapy ; Rare Diseases ; Recurrence ; Rhabdomyosarcoma ; Sarcoma ; Young Adult

OBJECTIVES: The objective of this study was to investigate clinical and neuropsychological factors associated with treatment response and adverse events of atomoxetine in children with attention-deficit/hyperactivity disorder (ADHD) in Korea. METHODS: Children with ADHD were recruited at the Department of Psychiatry of Asan Medical Center from April 2015 to April 2018. Diagnoses of ADHD and comorbid psychiatric disorders were confirmed with the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. The subjects were subsequently treated with atomoxetine for 12 weeks and illness severity was scored using the ADHD Rating Scale, Clinical Global Impression-Severity scale (CGI-S) and/or Improvement scale (CGI-I), at pre- and post-treatment. They also completed the Advanced Test of Attention (ATA), while their caregivers completed the Korean Personality Rating Scale for Children (KPRC) at pre- and post-treatment. Independent t-test, Fisher's exact test, χ2 test, mixed between-within analysis of variance and correlation analysis were used for statistical analysis. RESULTS: Sixty-five children with ADHD (mean age: 7.9±1.4 years, 57 boys) were enrolled, of which, 33 (50.8%) were treatment responders. Scores on the social dysfunction subscale of the KPRC (p=0.021) and commission errors on the visual ATA (p=0.036) at baseline were higher in treatment non-responders than in responders; however, the statistical significances disappeared after adjusting for multiple comparisons. Mood changes were also observed in 13 subjects (20.0%), and three of them discontinued atomoxetine due to this. Additionally, atomoxetine-emergent mood change was observed more frequently in girls (p=0.006), while the intelligence quotient (p=0.040) was higher in those subjects with mood changes than in those without. CONCLUSION: The results of our study suggest that clinical and neuropsychological factors could be associated with treatment response or adverse events of atomoxetine in children with ADHD. Further long-term studies with larger samples are needed.
Atomoxetine Hydrochloride ; Caregivers ; Child ; Chungcheongnam-do ; Diagnosis ; Female ; Humans ; Intelligence ; Korea ; Mood Disorders

OBJECTIVES: We examined the factor structure of the Adolescent version of the General Behavior Inventory (A-GBI) for Koreans. METHODS: We retrospectively reviewed the medical records of 220 adolescents (age, 12–18 years) who completed the A-GBI through the Department of Psychiatry at Asan Medical Center, Seoul, Korea, from October 2011 to December 2018. Caregivers of the study participants completed the Parent version of the GBI (P-GBI) 10-item Mania Scale. The adolescents were evaluated based on the A-GBI, Children's Depression Inventory (CDI), and Revised-Children's Manifest Anxiety Scale (RCMAS). Subsequently, an exploratory factor analysis (EFA) using the maximum likelihood method with direct oblimin rotation and correlation analyses with other scales were performed. RESULTS: The EFA identified a two-factor structure as having the best fit: factor I included depressive symptoms and factor II included hypomanic/biphasic symptoms. Factor I was very strongly correlated with the A-GBI depressive subscale (r=0.990, p<0.001) and strongly correlated with CDI (r=0.764, p<0.001) and RCMAS (r=0.666, p<0.001). Factor II was also very strongly correlated with the A-GBI hypomanic/biphasic subscale (r=0.877, p<0.001) and weakly correlated with CDI (r=0.274, p<0.001) and RCMAS (r=0.332, p<0.001). CONCLUSION: The above findings support a two-dimensional model of mood symptoms in Korean youth.
Adolescent ; Bipolar Disorder ; Caregivers ; Chungcheongnam-do ; Depression ; Factor Analysis, Statistical ; Fibrinogen ; Humans ; Korea ; Manifest Anxiety Scale ; Medical Records ; Methods ; Parents ; Prothrombin ; Retrospective Studies ; Seoul ; Weights and Measures

The Korean Medical Association (KMA) operates two organizations dedicated to healthcare policy research: the Research Institute for Healthcare Policy, which was launched in 2002, and the KMA Policy Special Committee, which was launched in 2017 as an administrative subunit of the board of representatives. Some members of the KMA have criticized the coexistence of two organizations for policy development. They argue that it would be preferable to unify these organizations, pointing out that having duplicate organizations for policy development wastes financial resources, disperses professionals, and produces different opinions on policies, which could be a source of confusion in the policy activities of the KMA. The author was a director in charge of policy at the KMA in 2002, when the Research Institute for Healthcare Policy was founded, and has also been an active member of the KMA Policy Special Committee since its launch in 2017. Having been involved in both policy development organizations, the author suggests that unifying these two organizations would not be desirable for the medical profession. The Research Institute for Healthcare Policy and the KMA Policy Special Committee are similar in that they deal with healthcare policy, but their approaches are quite distinct. The former organization must thoroughly research healthcare policy from a theoretical perspective, while the latter approaches healthcare policy by advocating for the interests of the members of the KMA. For instance, if the two organizations simultaneously research the possibility of a global budget payment system, the Research Institute for Healthcare Policy should address both its advantages and disadvantages, while the KMA Policy Special Committee would instead organize a policy initiative opposing a global budget payment system by focusing on its disadvantage of restricting the autonomy of healthcare providers. However, if the former organization provides a theoretical base and the latter organization coordinates policy advocacy in the interest of members of the KMA, the two organizations will make a major contribution to improving the medical environment in a complementary manner. In 2018, the two organizations jointly held a workshop with the theme of “shared growth”in Cheonan, demonstrating their ongoing efforts to collaborate. The author suggests that instead of becoming enmeshed in controversies about whether it should continue to exist as a separate organization, the KMA Policy Special Committee should instead focus on becoming the KMA's center for healthcare policy advocacy as soon as possible.
Academies and Institutes ; Budgets ; Chungcheongnam-do ; Delivery of Health Care ; Education ; Health Personnel ; Health Policy ; Humans ; Policy Making ; Professionalism

BACKGROUND: Kidney transplantation is an effective renal replacement therapy for patients with end-stage renal disease (ESRD). In this study, we assessed the impact of the baseline characteristics and comorbidities of ESRD patients on the probability of deceased donor kidney transplantation (DDKT) and evaluated the morbidity and mortality during the time spent waiting. METHODS: The study population consisted of 544 ESRD patients on the waiting list for DDKT at Chungnam National University Hospital in South Korea between February 2000 and October 2015. The patients were observed from the date of transplantation list registration to the date of transplantation. Baseline characteristics and comorbidities were investigated together with new-onset comorbidities that occurred during the waiting time. RESULTS: Diabetes mellitus (39.0%), hypertension (25.2%), and glomerulonephritis (21.3%) were the three most common causes of ESRD in this study, and coronary artery disease (9.4%) was the most common comorbidity. The 115 patients (19.3%) who underwent DDKT had a mean waiting time of 1,711 days (768–2,654 days or 4.68 years [2.10–7.27]). Blood groups other than type O, peritoneal dialysis, and nondiabetic ESRD were significantly associated with a higher likelihood of DDKT. Infection was the leading cause of death and the most common comorbidity that arose during the waiting time. Patients who experienced cardiovascular events during the waiting time showed a lower transplant rate compared with those who did not. CONCLUSION: The prevalence of comorbidities was high in renal transplantation candidates. During the often-long waiting time, new comorbidities may occur, with long-term sequelae limiting access to kidney transplantation or resulting in death.
Blood Group Antigens ; Cause of Death ; Chungcheongnam-do ; Comorbidity ; Coronary Artery Disease ; Diabetes Mellitus ; Glomerulonephritis ; Humans ; Hypertension ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney ; Korea ; Mortality ; Peritoneal Dialysis ; Prevalence ; Renal Replacement Therapy ; Tissue Donors ; Waiting Lists

OBJECTIVE: To compare the reliability and validity of the Korean range of motion standard protocol (KRSP) for measuring joint range of motion (ROM) with those of the conventional ROM measurement using a goniometer.METHODS: We conducted a randomized controlled trial involving 91 healthy elderly individuals. We compared two strategies of measuring joint ROM to evaluate the reliability and validity of each standardized protocol: first, the KRSP based on the Chungnam National University guidelines and second, handheld goniometric measurement. In the first strategy, 3 examiners (1 rehabilitation doctor, 1 physical therapist, and 1 physical therapy student) independently measured joint ROM in 46 randomly selected subjects; in the second strategy, another 3 examiners (1 rehabilitation doctor, 1 physical therapist, and 1 physical therapy student) measured joint ROM in 45 randomly selected subjects. The reliability of each protocol was calculated using intraclass correlation coefficient, ICC(2,1), and root mean square error (RMSE).RESULTS: Both protocols showed good to excellent intra-rater reliability. With goniometer use, the inter-rater reliability was low—ICC(2,1), 95% confidence interval ranged from 0.643 (0.486–0.783) to -0.078 (-0.296–0.494)— and RMSE was high. With the KRSP, the inter-rater reliability ranged from 0.846 (0.686–0.931) to 0.986 (0.972–0.994) and RMSE was low.CONCLUSION: ROM measurements using the KRSP showed excellent reliability. These results indicate that this protocol can be the reference standard for measuring ROM in clinical settings as an alternative to goniometers.
Aged ; Chungcheongnam-do ; Humans ; Joints ; Methods ; Physical Therapists ; Range of Motion, Articular ; Rehabilitation ; Reproducibility of Results

PURPOSE: Although an increased incidence of gallbladder (GB) stone formation after gastrectomy has been reported, its etiology remains uncertain. The goal of this study was to explore the incidence of gallstone formation after gastrectomy in gastric cancer patients and investigate the risk factors therein.MATERIALS AND METHODS: Medical records of patients who underwent curative gastrectomy, performed by a single surgeon between August 2012 and December 2015 at the Asan Medical Center, were retrospectively reviewed. Baseline characteristics and surgical outcomes, including GB stone gallstone formation after gastrectomy, were analyzed.RESULTS: Of 561 patients included in the study, 36 presented with GB stone formation after gastrectomy for gastric cancer. The incidence of gallstone formation was 6.4%. The mean interval between gallstone formation and gastrectomy was 21.9 months. In multivariate analyses, the incidence of gallstone formation increased in patients 63 years or older, with greater than 6.2 kg weight loss in the first 6 months after the procedure, a preoperative serum total bilirubin level greater than 0.5 mg/dL, and in patients who did not receive adjuvant chemotherapy.CONCLUSIONS: This study presented risk factors for GB stone formation after gastric cancer surgery, and special attention should be afforded to patients with such risk factors.
Bilirubin ; Chemotherapy, Adjuvant ; Cholecystolithiasis ; Chungcheongnam-do ; Gallbladder ; Gallstones ; Gastrectomy ; Humans ; Incidence ; Medical Records ; Multivariate Analysis ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms ; Weight Loss