BACKGROUND: To identify work sectors with high risk for work-related musculoskeletal disorders (MSDs) in Korean men and women. METHODS: We analyzed nationwide data to identify ergonomic risk factors in Korean employees. In particular, we analyzed data on exposure to five ergonomic risk factors (painful/tiring postures, lifting/moving heavy materials, standing/walking, repetitive hand/arm movements, and hand/arm vibration) according to employment sector, sex, and age, using the 2014 Fourth Korean Working Conditions Survey. We also used workers' compensation data on work-related MSDs in 2010, which is available by sex. RESULTS: The different work sectors had different gender distributions. “Manufacturing” (27.7%) and “construction” (11.3%) were dominated by males, whereas “human health and social work activities” (12.4%), “hotel and restaurants” (11.7%), and “education” (10.4%) were dominated by females. However, “wholesale and retail trade” and “public administration and defense” employed large numbers of males and females. Furthermore, the work sectors with a greater proportion of work-related MSDs and with multiple ergonomic risk factors were different for men and women. For men, “construction” and “manufacturing” had the highest risk for work-related MSDs; for women, “hotel and restaurants” had the highest risk for work-related MSDs. CONCLUSION: Ergonomic interventions for workers should consider gender and should focus on work sectors with high risk for MSDs, with multiple ergonomic risk factors, and with the largest number of workers.
Employment ; Female ; Humans ; Male ; Posture ; Risk Factors ; Social Work ; Workers' Compensation

BACKGROUND: Long working hours adversely affect worker safety and health. In 2004, Korea passed legislation that limited the work week to 40 hours, in an effort to improve quality-of-life and increase business competitiveness. This regulation was implemented in stages, first for large businesses and then for small businesses, from 2004 to 2011. We previously reported that average weekly working hours decreased from 2006 to 2010, based on the Korean Working Conditions Survey. METHODS: In the present study, we examine whether average weekly working hours continued to decrease in 2014 based on the 2014 Korean Working Conditions Survey. RESULTS: The results show that average weekly working hours among all groups of workers decreased in 2014 relative to previous years; however, self-employed individuals and employers (who are not covered by the new legislation) in the specific service sectors worked > 60 h/wk in 2014. CONCLUSION: The Korean government should prohibit employees from working excessive hours and should also attempt to achieve social and public consensus regarding work time reduction to improve the safety, health, and quality-of-life of all citizens, including those who are employers and self-employed.
Commerce ; Consensus ; Korea* ; Small Business

BACKGROUND: South Korea's population is aging more rapidly than any other country. Aging of the productive population will lead to shortage of labor and the decreasing quality of the labor force in South Korea. South Korea needs health care strategies to support the establishment of work environments that are appropriate for elderly workers who have reduced physical capacity. This paper aims to identify occupations that are dominated by aged workers and assess the exposure to hazards and work-related health problems of aged workers in these occupations. METHODS: We identified the 20 occupations in South Korea that employ the most aged workers (at least 55 years-old), among all 149 occupations that are defined as minor categories (identified by three digits) by the Korean Standard Classification of Occupations (KSCO). Exposure to hazards and work-related health problems of individuals in these occupations were evaluated by analyzing the results of the fourth Working Conditions Survey of 2014. RESULTS: Among the 20 occupations that employ the most aged workers, ‘Elementary Occupations', which the KSCO classifies as major category (9), had the largest proportion of aged workers. After this, there were five occupations of skilled manual workers and six occupations of skilled non-manual workers. Aged workers in elementary and skilled manual occupations reported frequent exposure to job-specific hazards, such as noise, vibrations, high and low temperatures, solvents, and chemicals. Relative to other workers, aged workers in the occupations reported more frequent exposure to ergonomic hazards, such as tiring or painful positions, carrying or moving heavy loads, and repetitive movements, and also reported more work-related musculoskeletal disorders and general fatigue. Injury due to accident was common in machinery-handling occupations. CONCLUSION: Job-specific hazards should be reduced to prevent occupation-related disorders in elementary and skilled manual occupations that are dominated by aged workers.
Aged ; Aging ; Classification ; Delivery of Health Care ; Employment ; Fatigue ; Humans ; Korea* ; Noise ; Occupations* ; Solvents ; Vibration

Purpose: The aim of this study was to analyze changes in stump length over time in patients with saphenous vein incompetence treated with cyanoacrylate closure (CAC) or radiofrequency ablation (RFA). Materials and Methods: We retrospectively analyzed data collected from patients with saphenous vein incompetence who underwent either CAC or RFA at Seoul National University Hospital between November 2015 and December 2018. The stump lengths were measured using duplex ultrasonography (DUS) within 1 month and 6 months after treatment. The Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ) score were used to assess clinical outcomes. Results: A total of 97 veins (64 great saphenous veins and 33 small saphenous veins) were analyzed. The stump length was not significantly different between the two groups at <1 month (P=0.311). However, the stump length in the CAC group was significantly longer than that in the RFA group at 6 months (P=0.004).At 6 months, the mean change in stump length was 1.41±2.28 cm in the CAC group and 0.51±0.54 cm in the RFA group (P=0.006). The VCSSs and AVVQ scores significantly improved after both procedures but were not significantly different between the two groups. Conclusion DUS at 6 months after treatment showed that the stump length in the CAC group increased more than that in the RFA group. No other factors affected the changes in stump length.

Purpose: The aim of this study was to analyze changes in stump length over time in patients with saphenous vein incompetence treated with cyanoacrylate closure (CAC) or radiofrequency ablation (RFA). Materials and Methods: We retrospectively analyzed data collected from patients with saphenous vein incompetence who underwent either CAC or RFA at Seoul National University Hospital between November 2015 and December 2018. The stump lengths were measured using duplex ultrasonography (DUS) within 1 month and 6 months after treatment. The Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ) score were used to assess clinical outcomes. Results: A total of 97 veins (64 great saphenous veins and 33 small saphenous veins) were analyzed. The stump length was not significantly different between the two groups at <1 month (P=0.311). However, the stump length in the CAC group was significantly longer than that in the RFA group at 6 months (P=0.004).At 6 months, the mean change in stump length was 1.41±2.28 cm in the CAC group and 0.51±0.54 cm in the RFA group (P=0.006). The VCSSs and AVVQ scores significantly improved after both procedures but were not significantly different between the two groups. Conclusion DUS at 6 months after treatment showed that the stump length in the CAC group increased more than that in the RFA group. No other factors affected the changes in stump length.

OBJECTIVE: Working memory impairments serve as prognostic factors for patients with schizophrenia. Working memory deficits are mainly associated with gray matter (GM) thickness and volume. We investigated the association between GM diffusivity and working memory in controls and individuals with schizophrenia. METHODS: T1 and diffusion tensor images of the brain, working memory task (letter number sequencing) scores, and the demographic data of 90 individuals with schizophrenia and 97 controls were collected from the SchizConnect database. T1 images were parcellated into the 68 GM Regions of Interest (ROI). Axial Diffusivity (AD), Fractional Anisotropy (FA), Radial Diffusivity (RD), and Trace (TR) were calculated for each of the ROIs. RESULTS: Compared to the controls, schizophrenia group showed significantly increased AD, RD, and TR in specific regions on the frontal, temporal, and anterior cingulate area. Moreover, working memory was negatively correlated with AD, RD, and TR in the lateral orbitofrontal, superior temporal, inferior temporal, and rostral anterior cingulate area on left hemisphere in the individuals with schizophrenia. CONCLUSION: These results demonstrated GM microstructural abnormalities in the frontal, temporal, and anterior cingulate regions of individuals with schizophrenia. Furthermore, these regional GM microstructural abnormalities suggest a neuropathological basis for the working memory deficits observed clinically in individuals with schizophrenia.
Anisotropy ; Brain ; Diffusion ; Diffusion Tensor Imaging ; Gray Matter ; Gyrus Cinguli ; Humans ; Memory, Short-Term ; Schizophrenia

Background: Mass spectrometry methods exhibit higher accuracy and lower variability than immunoassays at low testosterone concentrations. We developed and validated an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay for quantifying serum total testosterone. Methods: We used an ExionLC UPLC (Sciex, Framingham, MA, USA) system and a Sciex Triple Quad 6500+ (Sciex) MS/MS system in electrospray ionization and positive ion modes with multiple reaction monitoring transitions to evaluate precision, accuracy, linearity, lower limit of quantitation (LLOQ), carryover, ion suppression, stability, and reference intervals. For method comparison, we measured serum testosterone concentrations using this method in 40 subjects whose testosterone concentrations ranged from 0.14 to 55.48 nmol/L as determined using the Architect i2000 immunoassay (Abbott Diagnostics, Abbott Park, IL, USA) and in an additional 160 sera with testosterone concentrations <1.67 nmol/L. Results: The intra- and inter-run precision CVs were <2.81%, and the accuracy bias values were <3.85%, which were all acceptable. The verified linear interval was 0.03–180.84 nmol/L; the LLOQ was 0.03 nmol/L. No significant carryover and ion suppression were observed. The testosterone in serum was stable at 4°C, at –20°C, and after three freeze-thaw cycles. The reference intervals were successfully verified. The correlation was good at testosterone concentrations of 0.14–55.48 nmol/L; however, the Architect assay showed positive percent bias at concentrations <1.67 nmol/L. Conclusions The UPLC-MS/MS assay shows acceptable performance, with a lower LLOQ than the immunoassay. This method will enable the quantitation of low testosterone concentrations.

Objective: This study was performed to evaluate the efficacy and safety of lurasidone (160 mg/day) compared to quetiapine XR (QXR; 600 mg/day) in the treatment of acutely psychotic patients with schizophrenia. Methods: Patients were randomly assigned to 6 weeks of double-blind treatment with lurasidone 160 mg/day (n=105) or QXR 600 mg/day (n=105). Primary efficacy measure was the change from baseline to week 6 in Positive and Negative Syndrome Scale (PANSS) total score and Clinical Global Impressions severity (CGI-S) score. Adverse events, body measurements, and laboratory parameters were assessed. Results: Lurasidone demonstrated non-inferiority to QXR on the PANSS total score. Adjusted mean±standard error change at week 6 on the PANSS total score was -26.42±2.02 and -27.33±2.01 in the lurasidone and QXR group, respectively. The mean difference score was -0.91 (95% confidence interval -6.35–4.53). The lurasidone group showed a greater reduction in PANSS total and negative subscale on week 1 and a greater reduction in end-point CGI-S score compared to the QXR group. Body weight, body mass index, and waist circumference in the lurasidone group were reduced, with significantly lower mean change compared to QXR. Endpoint changes in glucose, cholesterol, triglycerides, and low-density lipoprotein levels were also significantly lower. The most common adverse drug reactions with lurasidone were akathisia and nausea. Conclusion Lurasidone 160 mg/day was found to be non-inferior to QXR 600 mg/day in the treatment of schizophrenia with comparable efficacy and tolerability. Adverse effects of lurasidone were generally tolerable, and beneficial effects on metabolic parameters can be expected.