This study investigates whether personality characteristics and learning behaviors can predict medical students’ academic achievement in Korea, specifically in terms of successfully completing medical school without delays or achieving a high grade point average (GPA) in their final year. In May 2018, 316 medical students took the Multi-Dimensional Learning Strategy Test, 2nd edition, which provided data on their personality and learning behavioral characteristics. Their final year’s GPA and any delays in completing medical school were ascertained by reviewing all electronic academic records of each semester they had been enrolled. The combination of personality and learning behavioral characteristics was significantly associated with completing medical school without delays, even after adjusting for sex and admission path. A multiple logistic regression analysis showed that the adjusted odds ratios and 95% confidence intervals for completing medical school without delays were 1.52 (95% confidence interval [CI], 0.83–2.78) and 3.64 (95% CI, 1.70–7.82) for “others” and “both high” categories, respectively, when compared with the “both low” category. For 235 students who completed medical school without delays, their learning behavioral characteristics (scores) were significantly associated with their final year’s GPA even after adjusting for sex, admission path, and personality characteristics (scores) as determined by the multiple linear regression analysis. This study suggests that individual personality and learning behavior characteristics are predictors of medical students’ academic achievement. Therefore, interventions such as personalized counseling programs should be provided in consideration of such student characteristics.

Background: To deliver therapeutics into the brain, it is imperative to overcome the issue of the blood-brain-barrier (BBB). One of the ways to circumvent the BBB is to administer therapeutics directly into the brain parenchyma. To enhance the treatment efficacy for chronic neurodegenerative disorders, repeated administration to the target location is required. However, this increases the number of operations that must be performed. In this study, we developed the IntraBrain Injector (IBI), a new implantable device to repeatedly deliver therapeutics into the brain parenchyma. Methods: We designed and fabricated IBI with medical grade materials, and evaluated the efficacy and safety of IBI in 9 beagles. The trajectory of IBI to the hippocampus was simulated prior to surgery and the device was implanted using 3D-printed adaptor and surgical guides. Ferumoxytol-labeled mesenchymal stem cells (MSCs) were injected into the hippocampus via IBI, and magnetic resonance images were taken before and after the administration to analyze the accuracy of repeated injection. Results: We compared the planned vs. insertion trajectory of IBI to the hippocampus.With a similarity of 0.990 ± 0.001 (mean ± standard deviation), precise targeting of IBI was confirmed by comparing planned vs. insertion trajectories of IBI. Multiple administrations of ferumoxytol-labeled MSCs into the hippocampus using IBI were both feasible and successful (success rate of 76.7%). Safety of initial IBI implantation, repeated administration of therapeutics, and long-term implantation have all been evaluated in this study. Conclusion Precise and repeated delivery of therapeutics into the brain parenchyma can be done without performing additional surgeries via IBI implantation.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) may cause changes in the shape of the thoracic cage by increasing lung volume and hyperinflation. This study investigated changes in thoracic cage dimensions and related factors in patients with COPD. METHODS: We enrolled 85 patients with COPD (76 males, 9 females; mean age, 70.6±7.1 years) and 30 normal controls. Thoracic cage dimensions were measured using chest computed tomography at levels 3, 6, and 9 of the thoracic spine. We measured the maximal transverse diameter, mid-sagittal anteroposterior (AP) diameter, and maximal AP diameter of the right and left hemithorax. RESULTS: The average AP diameter was significantly greater in patients with COPD compared with normal controls (13.1±2.8 cm vs. 12.2±1.13 cm, respectively; p=0.001). The ratio of AP/transverse diameter of the thoracic cage was also significantly greater in patients with COPD compared with normal controls (0.66±0.061 vs. 0.61±0.86; p=0.002). In COPD patients, the AP diameter of the thoracic cage was positively correlated with body mass index (BMI) and 6-minute walk test distance (r=0.395, p<0.001 and r=0.238, p=0.028) and negatively correlated with increasing age (r=−0.231, p=0.034). Multiple regression analysis revealed independent correlation only between BMI and increased ratio of AP/transverse diameter of the thoracic cage (p<0.001). CONCLUSION: Patients with COPD exhibited an increased AP diameter of the thoracic cage compared with normal controls. BMI was associated with increased AP diameter in these patients.
Body Mass Index ; Female ; Humans ; Lung ; Male ; Pulmonary Disease, Chronic Obstructive* ; Spine ; Thorax ; Tomography, X-Ray Computed

BACKGROUND AND OBJECTIVES: Numbness on the hand occurs infrequently after a transradial cardiac catheterization (TRC). The symptom resembles that of neuropathy. We, therefore, investigated the prevalence, the predicting factors and the presence of neurological abnormalities of numbness, using a nerve conduction study (NCS). SUBJECTS AND METHODS: From April to December 2013, all patients who underwent a TRC were prospectively enrolled. From among these, the patients who experienced numbness on the ipsilateral hand were instructed to describe their symptoms using a visual analogue scale; subsequently, NCSs were performed on these patients. RESULTS: Of the total 479 patients in the study sample, numbness occurred in nine (1.8%) following the procedure. The NCS was performed for eight out of the nine patients, four (50%) of which had an abnormal NCS result at the superficial radial nerve. A larger sheath and history of myocardial infarction (p=0.14 and 0.08 respectively) tended towards the occurrence of numbness; however, only the use of size 7 French sheaths was an independent predictor for the occurrence of numbness (odds ratio: 5.50, 95% confidence interval: 1.06-28.58, p=0.042). The symptoms disappeared for all patients but one, within four months. CONCLUSION: A transient injury of the superficial radial nerve could be one reason for numbness after a TRC. A large sheath size was an independent predictor of numbness; therefore, large sized sheaths should be used with caution when performing a TRC.
Cardiac Catheterization* ; Cardiac Catheters* ; Hand ; Humans ; Hypesthesia* ; Myocardial Infarction ; Neural Conduction* ; Prevalence ; Prospective Studies ; Radial Nerve* ; Radial Neuropathy

OBJECTIVE: The aim of the present study was to investigate differences in discontinuation time among antidepressants and total antidepressant discontinuation rate of patients with depression over a 6 month period in a naturalistic treatment setting. METHODS: We reviewed the medical records of 900 patients with major depressive disorder who were initially prescribed only one kind of antidepressant. The prescribed antidepressants and the reasons for discontinuation were surveyed at baseline and every 4 weeks during the 24 week study. We investigated the discontinuation rate and the mean time to discontinuation among six antidepressants groups. RESULTS: Mean and median overall discontinuation times were 13.8 and 12 weeks, respectively. Sertraline and escitalopram had longer discontinuation times than that of fluoxetine, and patients who used sertraline discontinued use significantly later than those taking mirtazapine. No differences in discontinuation rate were observed after 24 weeks among these antidepressants. About 73% of patients discontinued antidepressant treatment after 24 weeks. CONCLUSION: Sertraline and escitalopram tended to have longer mean times to discontinuation, although no difference in discontinuation rate was detected between antidepressants after 24 weeks. About three-quarters of patients discontinued antidepressant maintenance therapy after 24 weeks.
Antidepressive Agents* ; Citalopram ; Depression ; Depressive Disorder, Major* ; Fluoxetine ; Humans ; Medical Records ; Sertraline

BACKGROUND/AIMS: The prevalence of hepatitis C virus (HCV) infection in Busan, Gyeongnam, and Jeonnam Provinces in Korea is more than twice the national average. This study aimed to examine whether demographic and lifestyle characteristics are associated with HCV infection in these areas. METHODS: A case control study was performed at three study hospitals. HCV cases were matched with two controls for sex and age. Patient controls were selected from non-HCV patients at the same hospital. Healthy controls were subjects participating in medical checkups. Conditional logistic regression models were used. RESULTS: A total of 234 matched-case and patient- and healthy-control pairs were analyzed. The significant risk factors for both controls were sharing razors (adjusted odds ratio [aOR], 2.39 and 3.29, respectively) and having more than four lifetime sexual partners (aOR, 2.15 and 6.89, respectively). Contact dockworkers (aOR, 1.91) and tattoos (aOR, 2.20) were significant risk factors for the patient controls. Transfusion (aOR, 5.38), a bloody operation (aOR, 5.02), acupuncture (aOR, 2.08), and piercing (aOR, 5.95) were significant risk factors for the healthy controls. Needle stick injuries and intravenous drug abuse were significant in the univariate analysis. CONCLUSIONS: More education concerning the dangers of sharing razors, tattoos and piercings is required to prevent HCV infection. More attention should be paid to needle stick injuries in hospitals and the community.
Acupuncture Therapy/adverse effects ; Adult ; Aged ; Blood Transfusion/adverse effects ; Body Piercing/adverse effects ; Case-Control Studies ; Equipment Reuse ; Female ; *Hepacivirus ; Hepatitis C/*epidemiology/*transmission/virology ; Humans ; Life Style ; Logistic Models ; Male ; Middle Aged ; Needlestick Injuries/complications/virology ; Odds Ratio ; Prevalence ; Republic of Korea/epidemiology ; Risk Factors ; Sexual Behavior ; Sexual Partners ; Tattooing/adverse effects ; Workplace ; Young Adult

OBJECTIVES: The objectives of this study were to evaluate the effect of smoking on utilization of and expenses in ambulatory dental care. METHODS: The subjects of this study were 5,751 men aged over 20 years selected from the Korea Health Panel data collected during 2010-2012. Pack-years of smoking were calculated based on the survey data. Dental utilization was defined as dental outpatient clinic use least once in three years. The expenses in ambulatory dental care were summed to determine total dental health care spending for three years. To detect the effect of smoking, we used multiple logistic regression analysis for dental utilization and multiple linear regression for expenses in ambulatory dental care after changing log. RESULTS: The pack-years had a significant effect on dental utilization and expenses in participants aged 40-59 years. After controlling for income level, bedtime brushing, and the presence of chronic disease, dental care utilization rates in the over 10 to less than 25 pack-year and the over 25 pack-year groups were about 1.4 (OR=1.37, (P =0.007)) and 1.6 times (OR=1.59, (P =0.001)) those in the 0 pack-year group. In comparison with the 0 pack-year group, the over 10 to less than 25 pack-year group spent 50,000 won more over dental expenses, while the corresponding number for the over 25 pack-year group was about 100,000 won. Thus, the ambulatory dental care expenses increased with the packyears of smoking. CONCLUSIONS: Smoking significantly influenced the utilization and expense in ambulatory dental care in men aged 40-59 years.
Ambulatory Care Facilities ; Chronic Disease ; Delivery of Health Care ; Dental Care* ; Humans ; Korea ; Linear Models ; Logistic Models ; Male ; Smoke* ; Smoking*

BACKGROUND/AIMS: This study compared the prevalence of hepatitis C virus (HCV) infection in the Republic of Korea and estimated the high-risk regions and towns. METHODS: National Health Insurance Service data for 8 years from 2005 to 2012 were used. The subjects of the study had visited medical facilities and been diagnosed with or received treatment for acute or chronic HCV as a primary or secondary disease according to ICD-10 codes of B17.1 or B18.2, respectively. Any patient who received treatment for the same disease multiple times during 1 year was counted as one patient in that year. To correct for the effect of the age structure of the population by year and region, the age-adjusted prevalence was calculated using the direct method based on the registered population in 2010. RESULTS: The overall prevalence of HCV infection among Korean adults (>20 years old) increased from 0.14% in 2005 to 0.18% in 2012. The sex-, age-, and region-adjusted prevalence in 2012 was 0.18%. The prevalence was highest in Busan, Jeonnam, and Gyeongnam, and there were towns with noticeably higher prevalences within these regions: Jindo (0.97%) in Jeonnam, Namhae (0.90%) in Gyeongnam, and Seo-gu (0.86%) in Busan. CONCLUSIONS: The prevalence of HCV infection differs by regions as well as towns in the Republic of Korea, and is highest in Busan, Jeonnam, and Gyeongnam. The reasons for the high prevalence in these specific regions should be identified, since this could help prevent HCV infections in the future. In addition, active surveillance and treatment policies should be introduced to stop any further spread of infection in these high-prevalence regions.
Adult ; Age Factors ; Aged ; Databases, Factual ; Female ; Hepatitis C/*diagnosis/*epidemiology ; Humans ; Male ; Middle Aged ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; Sex Factors ; Young Adult