BACKGROUND: The purpose of this study was to investigate the effect of shift work on occupational safety in various industrial sectors. The study analyzes the effects of shift work on the health of workers by considering factors such as the workplace environment and welfare. METHODS: Focusing on the 4(th) Korean Working Conditions Survey, this study used an ordinary least-square multiple regression analysis. The dependent variable was the annual frequency of injuries reported by workers. Independent variables were categorized as demographic, shift work, workplace environment, and welfare variables. The analysis was conducted on two levels: 1) Shift work and nonshift work groups were compared, and 2) Shift work was compared with fixed and rotating shifts. RESULTS: For the entire group, age, a low level of education, work hours, and daily and dispatch work negatively impacted the frequency of injuries. Shift work was negatively affected by workplace environment and welfare factors. In the shift group, the frequency of injuries was lower than that of regular workers, and the higher the autonomy in the choice of work hours, the lower the frequency of injuries. Furthermore, shift workers in Korea have more extended work hours (49.25 h/week) than other workers (46.34 h/week). CONCLUSION: Overall, welfare factors such as workplace satisfaction and work–life balance reduced the frequency of injuries. The effect of shift work was limited, but it was confirmed that shift worker autonomy could reduce the frequency of injuries.
Education ; Humans ; Korea* ; Occupational Health

No abstract available.
Bone Marrow* ; Necrosis*

BACKGROUND: An in-training examination is given annually to the all laboratory medicine residents of in Korea. The purpose of this study was to evaluate the results of the in-training examinations according to the examinees' postgraduate years, a number of teaching faculty members and hospital beds, and the score of the board examination. METHODS: A total number of examinees during the 5-year period from 2001 to 2005 were 311. All residents took the same in-training examinations given each year irrespective of the postgraduate year (PGY). RESULTS: The scores of in-training examinations increased with advance in the examinees' PGY (P<0.01). The scores were not different according to the size of teaching faculty or hospital beds (P>0.05). The correlation coefficients of each PGY scores were from 0.474 to 0.755 (P<0.01). The scores of the 4th PGY were correlated with those of the board examinations (r=0.627, P<0.001). CONCLUSIONS: These results suggest that the scores of the in-training examinations may be a valid measure of knowledge acquired by residents during their training years and provide a useful information for improving the laboratory medicine residency training program.
Education ; Internship and Residency* ; Korea

This study investigated how three Asian countries–Republic of Korea (ROK), Republic of China (Taiwan), and Singapore–considered as standouts, responded to the coronavirus disease 2019 (COVID-19) in terms of governance system, health sector innovation, and social distancing to draw lessons that other countries can learn from. The countries were commonly in success of the response in early stage of the pandemic thanks to their effective and efficient strategies paired with advanced information and communications technology (ICT). Consequently, the three jurisdictions reported lower confirmed cases as well as fatality rate of the infectious disease compared to other high-income countries. In addition, the countries’ previous experiences with other pandemics, including influenza A, Middle East respiratory syndrome, and severe acute respiratory syndrome, enabled them to establish resilient public health systems and gain public acceptance to governmental control or surveillance during national infectious disease-related crises outbreaks. Advanced ICT infrastructure and digital technology were used as effective tools for testing, tracing, and treatment of the pandemic in collaboration with the private sector as a crucial player. The ROK, Taiwan, and Singapore adopted different strategies between containment and mitigation policy to flatten the epidemic curves effectively according to their own situation and judgement. Despite the exemplary aspect of the three nations in coping with the COVID-19 pandemic, a few limitations were also observed in terms of vaccination and unequal consequences of the pandemic among people. These should be further discussed in order to be prepared for future pandemics.

OBJECTIVES: To analyze the treatment results of combined treatment with percutaneous vertebroplasty and adhesiolysis in the patients who happened the osteoporotic compression fractures during the conservative treatment of pre-existing degenerative spinal stenosis. MATERIALS AND METHODS: A retrospective review was carried out on 38 patients who happened the osteoporotic compression fractures during the conservative treatment of pre-existing degenerative spinal stenosis. We performed percutaneous vertebroplasty for osteoporotic compression fractures and adhesiolysis for degenerative spinal stenosis after 4 weeks after vertebroplasty. Radiologic results were evaluated by progression of compression rate, fractures in adjacent segment and change of the BMD. Clinical results were evaluated with Denis pain scale for osteoporotic compression fractures and Katz satisfaction scale for degenerative spinal stenosis. RESULTS: The compression rate was 30.2% preoperatively, 21.4% postoperatively, and 24.6% at 12 months postoperatively. There was no fracture in adjacent segment. Clinically, the Denis score were P3 in 13 and P4 in 25, preoperatively, P1 in 11 and P2 in 26, P3 in 1, postoperatively (P=0.03). In regard to degenerative diseases, the Kats scale were 38 to 5, 86.8% in low back pain (P=0.017) and 38 to 4, 89.4% in claudication (P=0.006). The overall Katz satisfaction scale was 81.5% at 12 months postoperatively. The BMD changes in patients who treated neuroplasty was not significant (P=0.175). CONCLUSIONS: The combined treatment with percutaneous vertebroplasty and adhesiolysis may be an effective treatment strategy for the osteoporotic compression fracture and spinal stenosis without surgical intervention in old age patients.
Fractures, Compression ; Humans ; Low Back Pain ; Retrospective Studies ; Spinal Stenosis ; Vertebroplasty

The present study reviews recently developed and commonly used methods for determination of body composition in vivo with relevance for nutritional assessment. Body composition measurement methods are continuously being improved, with the most commonly used methods being bioelectrical impedance analysis, dual energy X-ray absorptiometry, computed tomography, and magnetic resonance imaging or magnetic resonance spectroscopy. Recent developments include three-dimensional photonic scanning, quantitative magnetic resonance, and air displacement plethysmography. Collectively, these techniques allow for the measurement of fat, fat-free mass, bone mineral content, total body water, extracellular water, total adipose tissue and its subdepots (visceral, subcutaneous, and intermuscular), skeletal muscle, select organs, and ectopic fat depots.
Absorptiometry, Photon ; Adipose Tissue ; Body Composition ; Body Water ; Bone Density ; Electric Impedance ; Human Body ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Methods ; Muscle, Skeletal ; Nutrition Assessment ; Obesity ; Plethysmography ; Water

BACKGROUND: Early identification and appropriate management of mild chronic renal failure has been increasingly recognized as an important opportunity to delay the progression of renal disease. Many physicians rely on serum creatinine (Scr) as a screening test for renal impairment; however, Scr levels can remain within the normal range even when renal function is significantly impaired in certain group of patients. METHODS: The subjects were 20, 245 persons who were enrolled a regular health check up program, Jan. 1997 to Jun. 2001, at Ajou University Hospital, Korea. We identified GFR below 60 mL/min/1.73 m2 as abnormal and found the percentage of patients with Scr value from 1.1 mg/dL to 1.4 mg/dL and their sex and age distribution, using GFRs calculated by Cockroft-Gault Equation, MDRD Equation, and Kang's Equation. RESULTS: Average Scr was 1.07+-0.13 mg/dL in male and 0.82+-0.11 mg/dL in female. Among 34 University hospital in metro Seoul area, 11 hospital used 1.4 mg/dL as normal upper limit of Scr and 7 hospital used 1.3 mg/dL. Taking normal Scr upper limit as 1.3 or 1.4 mg/dL, the frequency of GFR below 60 mL/min/1.73 m2 was 3.9-50% in males and 75-100% in females, although some differences existed according to the equation used. CONCLUSION: Currently used normal Scr upper limit 1.3, 1.4 mL/dL was found to be much too high and we concluded a downward adjustment is needed and one-time test is not adequate to conclude renal impairment but several regular tests are required.
Age Distribution ; Creatinine* ; Female ; Glomerular Filtration Rate ; Humans ; Kidney Failure, Chronic ; Korea ; Male ; Mass Screening ; Reference Values* ; Seoul

Background: The risk of secondhand smoke (SHS) is gradually becoming apparent, and as smoking cessation zones are expanding, the exposure to SHS in workplaces, homes, and public places is decreasing. The objective of this study was to evaluate the actual exposure to SHS in nonsmokers. Methods: This study used data from 2008 to 2011 and 2014 to 2018 from the Korean National Health and Nutrition Examination Survey (KNHANES). The urine cotinine concentration values were compared by the geometric mean according to sex, age group, and rurality for non-smokers aged 19 years or older who were tested for urine cotinine. Results: The overall trend of urine cotinine concentration in Korean adult non-smokers have shown a decline since 2011. It gradually decreased from 2.82 ng/mL in 2010 to 0.50 ng/mL in 2016 but slightly increased to 0.79 ng/mL in 2018. Both male and female showed this trend. The decline tended to be lower in those aged 60 years and older, with higher urine cotinine concentrations in the recent 3 years in the rural than in urban residents. Conclusion The urinary cotinine concentration levels in Korean non-smokers increased from 2008 to 2010, then decreased till 2016, but gradually increased thereafter. This is possibly due to limiting the exposure to SHS through expanding the smoking area. Furthermore, a policy to lower the smoking rate with strict implementation and monitoring of the existing policy will be needed.

BACKGROUND: Friedewald equation is the most widely used method for estimating low-density lipoprotein cholesterol (LDL-C) level. However, due to potential over- or underestimation, many studies have used a modified equation. This study aimed to compare estimates by 4 different equations to directly measured LDL-C concentrations in order to propose the most appropriate method for LDL-C estimation in the Korean population. METHODS: We studied data of 4,350 subjects that included total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and LDL-C concentrations that had been measured at one university hospital in Seoul. We investigated 4 equations: LDL-C by Friedewald's original equation (LDL-C(F)) and its 3 modifications. Pearson correlation analysis was performed to compare these estimates to the direct measurement. RESULTS: Pearson correlation analysis revealed a good correlation among all 4 estimated LDL-C values and the directly measured LDL-C value. The Pearson coefficients were 0.951 for LDL-C(F), 0.917 for LDL-C by Hatta equation (LDL-C(H)), 0.968 for LDL-C by Puavilai equation (LDL-C(P)), and 0.983 for LDL-C by Martin equation (LDL-C(M)). Martin equation (LDL-C(M)) resulted in the best approximation (mean difference from the direct measurement, 5.5 mg/dL; mean percentage difference from the direct measurement, 5.1%) and the best agreement with the direct measurement (86.1%). LDL-C(P) resulted in the second-best approximation (mean difference, 7.0 mg/dL; mean percentage difference, 6.2%; concordance, 82.5%). LDL-C(M) was found to be less influenced by TG and HDL-C levels than by LDL-C(F). CONCLUSION: Estimates by Martin equation had the best agreement with direct LDL-C concentrations and both Martin and Puavilai equations were superior to Friedewald equation for estimating LDL-C concentrations in Korean adults.
Adult* ; Cholesterol* ; Dyslipidemias ; Humans ; Lipoproteins* ; Methods* ; Seoul ; Triglycerides

PURPOSE: To assess the inter-device agreement of peripapillary retinal nerve fiber layer (RNFL) thickness measurements by 2 spectral domain Cirrus HD optical coherence tomography (OCT) devices in healthy Korean subjects. METHODS: Eleven eyes of 11 healthy volunteers were enrolled in the present study. Each eye was scanned with the Optic Disc Cube 200 x 200 scan of 2 Cirrus HD OCT devices for peripapillary RNFL thickness calculation. The inter-device agreements of the 2 Cirrus HD OCTs for average, quadrant, and clock-hour RNFL thickness values were determined with Wilcoxon signed rank test, Friedman test, Cronbach's alpha (alpha), intraclass correlation coefficient (ICC), coefficient of variation (COV), and Bland-Altman plot. RESULTS: The mean age of the participants was 25.82 +/- 3.28 years and all had a 0.00 logarithm of the minimum angle of resolution of best-corrected visual acuity. The signal strengths of scans from the 2 Cirrus HD OCT were not significantly different (p = 0.317). The inter-device agreement of average RNFL thickness was excellent (alpha, 0.940; ICC, 0.945; COV, 2.45 +/- 1.52%). However, the agreement of nasal quadrant RNFL thickness was not very good (alpha, 0.715; ICC, 0.716; COV, 5.72 +/- 4.64%). Additionally, on the Bland-Atman plot, the extent of agreement of the 2 Cirrus HD OCTs for RNFL thickness was variable according to scanned sectors. CONCLUSIONS: The inter-device agreement of 2 spectral domain Cirrus HD OCT devices for peripapillary RNFL thickness measurements was generally excellent but variable according to the scanned area. Thus, physicians should consider this fact before judging a change of RNFL thicknesses if they were measured by different OCT devices.
Adult ; *Algorithms ; Female ; Humans ; Male ; Observer Variation ; Optic Nerve Diseases/*diagnosis ; Retinal Ganglion Cells/*pathology ; Tomography, Optical Coherence/methods/*statistics & numerical data ; Young Adult