• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.35.1-35.12
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• 2022

Background: Shift work is known to be associated with cardiovascular disease (CVD). It has been found that inflammatory reactions are involved in the onset and progression of CVD. Therefore, the purpose of this study was to investigate the association between shift work and inflammatory markers. Methods: Among workers at an electronics manufacturing company, 2,329 workers who had a health checkup from January 2019 to December 2019 were targeted. The general and biochemical characteristics of daytime workers and shift workers were compared through the Independent-test and the χ² test. Through multiple linear regression analysis, the association with shift work and inflammatory markers was investigated. Through multiple logistic regression analysis, the association with shift work and high inflammatory markers Results: The mean total leukocytes, neutrophils, monocytes, lymphocytes of shift workers were significantly higher than those of daytime worker. The mean high-sensitivity C-reactive protein (hs-CRP) of shift workers was also higher than that of daytime workers but not significantly. In multiple linear regression, shift work was associated with increase of total leukocyte count (β = 0.367, p < 0.001) and hs-CRP (β = 0.140, p = 0.005) after adjusting for all variables. In multiple logistic regression analysis, shift work showed 2.27 times risk of high leukocyte count and 1.8 times risk of high hs-CRP level compared to daytime work after adjusting for all variables. Conclusions: This study confirmed that shift work is associated with high inflammatory markers. Considering that high inflammatory markers is independent indicator of CVD, the association between shift work and high inflammatory markers may help to understand the CVD risk of shift workers.

• Women's Health Nursing
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• v.27 no.2
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• pp.113-127
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• 2021

Purpose: This study examined health behaviors, use of health services, and depression among women who perform daytime and shift work in Korea, as well as factors related to depression. Methods: We conducted a secondary analysis using data from the 2018 data of the 7th Korea National Health and Nutrition Examination Survey. Data on women, 1,493 regular daytime workers and 322 shift workers, were analyzed. Results: Women shift workers (χ²=43.97, p<.001), had a lower education level (χ²=45.56, p<.001), and lower personal income (χ²=16.85, p=.030) than their daytime counterparts. A higher proportion of shift workers were unmarried (χ²=37.47, p<.001) and they typically worked fewer than 40 hours per week (χ²=69.94, p<.001). The depression score of shift workers was higher than that of daytime workers (t=2.85, p=.005). A higher proportion of shift workers also drank alcohol (χ²=6.49, p=.032) and smoked (χ²=30.79, p<.001). Over 8% of shift workers typically slept fewer than 5 hours per night (χ²=14.17, p=.024). It was confirmed that depression in women shift workers was affected by age, personal income, marital status, health status, and smoking status, in addition to cancer screening participation, unmet medical care needs, and unmet dental care needs. Conclusion: More attention should be given to the health needs of women working shifts. Health promotion programs specific for women shift workers are needed to improve their physical and mental health, encourage use of medical care services, and improve public health policies and systems.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.188-196
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• 2005

Accident reports from 1991 to 2000 of a steel company were used to analyze which factors induce industrial accidents. The subjects were 8,311 blue-collar workers, who sustained 114 occupational injuries and work on a continuous full-day 3-team 3-shift system of backward rotation(mornings to afternoons to nights). With respect to marital status, the occupational injury rate(OIR) on the married workers was significantly higher compared to unmarried workers. With respect to no, the OIR of those in their early 20s was significantly higher when compared to other age groups. The OIR of highly educated workers showed a reduction when compared with lower educated workers. The OIR of shift workers were significantly higher compared with the daytime workers. The OIR of type of work decreased across the steel manufacturing process, rolling process, machine maintenance section forwarding products section to the field management section. With respect to the block of shift work(morning, afternoon, and night shifts) by the type of work, the OIR of the night shift was higher than those of the morning shift in the steel manufacturing process or forwarding products section. The OIR of the machine maintenance section was slightly higher in the morning shift than those of the night shift. The OIR of the time of day of the shift workers reached a peak between 09:00 and 11:00. The OIR of a slight injury to shift workers decreased across the night, afternoon, to morning shifts whereas the OIR of a serious injury tended to decrease across the night, morning, to afternoon shift. The body parts most commonly injured were the arm and the crus.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.279-286
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• 1991

Much of the working population in developing countries are engaged in shift work now and the number of shift workers is not expected to decrease in the future mostly because the need for continuity of production is increasing. Therefore, the possible effects of shift work on health are of particular interest, and in fact, there have been many epidemiological studies on shift work since the first world war. However, no studies on health effects of shift work have been reported in Korea, and the existing studies in western world have arrived at quite different conclusions mainly because the conditions of work other than shift work, such as age and selection of workers, work environment, and labor conditions also influence the health of workers. This study was firstly carried out in Korea to investigate the health risks related to shift work with 2,093 female workers randomly selected from three major manufacturing industries in proportion to total number of female workers in those industries. Differences of work conditions other than shift work in this study were adjusted by multivariate analysis. Ma findings obtained from this study are as follows : 1. There were significant differences between shift and day workers in the distribution of age, type of industry, condition of noise and dust, regularity of mealtime, working position, and working duration. Shift workers tended to be younger, to have shorter working duration, to have more irregular mealtime, to work in standing position, and to work under more noisy and dusty environment than day workers. 2. Univariate analysis showed that shift work increased the Todai Health Index (THI) scores of digestive tract, respiratory tract, and mental instability symptom categories. Shift work also increased days of sickness absence and number of industrial accident per 100 workers per month. 3. Multivariate analysis that adjusted the differences of demographic, occupational and non-occupational health-related working conditions showed that digestive tract symptom and mental instability symptom scores were significantly higher in shift workers than those in day workers. Based on these study results, it is concluded that the shift work has significant effects on some psychophysiological conditions of the workers and the effects are also influenced by several other personal and working conditions.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.231-245
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• 2006

Purpose : To investigate and compare the characteristics of menstruation in the shift workers and the day workers, and present guidelines for health promotion of the shift-working women. Methods : Questionnaires including general health condition and QSCC II were distributed to shift-working women and day-working women in one university hospital in Gyeonggi-do and 36 questionnaires of shift-working women and 33 of day-working women were analyzed. Results : Day workers were about 5 years older than shift workers on average. There was more irregularity of menstrual cycle and period in day-working group but it is thought to incorrect because of the age problem. There were more women who have dysmenorrhea in day-working group, but the proportion of dysmenorrhea which continues more than 72 hours -which is very suggestive of secondary dysmenorrhea- was higher in shift-working group. Average VAS of dysmenorrhea was nearly the same in two groups. The life of shift-working group was lesser satisfactory than that of day-working group. There were more sleep disturbances in the shift-working group. Sasang constitution was analyzed in both group using QSCC II, and Taeumin were more in shift-working group. Conclusion : As the number of shift-working women increases, needs for oriental medical treatments would increase because it is more natural and lesser invasive managements which women are very interested in. So it is thought to be necessary to understand health problems of shift-working women, and prepare guidelines for managements and treatments to promote the health of shift-working women.

• Journal of the Korean Dietetic Association
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• v.29 no.1
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• pp.13-30
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• 2023

This study investigates the effect of working hours on the dietary behaviors and dietary quality of male industrial workers employed in rotating shifts. The survey was conducted from February to March 2022, enrolling 209 male workers operating in rotational shifts at industries in the Chungcheongnam-do region. Eating behavior and health awareness were investigated during the morning shift, afternoon shift, and night shift for the same subjects. The shift timings were found to be associated with dietary behavior, which had an impact on the dietary quality of workers. Negative effects of shift timings on diet and health were also perceived by the shift workers. The frequency of alcohol consumption was high during the morning shift, and the frequency of night time snack intake was high during the afternoon shift. During the night shift, there was decreased vegetable intake and increased ramyeon intake. Compared to the morning shift, a significant decrease in dietary quality scores was found during the night shift. The workers recognized that rotating shift work negatively affected health, eating habits and sleep. There was a high demand for providing a variety of menus and healthy night snacks in the company cafeteria. When nutritional counseling and educational health services were provided, the willingness to participate was high. Therefore, to improve the health and dietary quality of shift workers, there is a need to provide diets suitable for the working environment and the characteristics, and to provide nutrition management services.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.55-61
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• 2007

The purpose of this study is to assess the welfare level for shift workers by means of their satisfactions to the jobs in manufacturing environment. As a measurement tool of job satisfaction, we use the JDI(Job Descriptive Index) which can ensure reliability and are widely used. Measurement factors are investigated by means of the duty, payment, promotion, supervisor, co-workers, and general job satisfaction of shift workers. For the application of job satisfaction, 109 workers, 12-hour shift workers in domestic five companies related with manufacturing industry are considered. They treat general facilities in night shift work. The result of this study may be used as a strategic data of welfare policy for improving the welfare level of shift workers.

• Research in Community and Public Health Nursing
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• v.18 no.2
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• pp.284-292
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• 2007

Purpose: The purpose of this study is to explore and understanding the nature of the shift workers' experience in industries requiring 24 hours-a-day service provision and support. For the Purpose, the present researcher made a research Question, "What are workers' experience in the shift work?" Methods: In the study, 5 male shift workers, 3 female shift worker and a woman (key informant) whose husband is a shift worker participated. Then profound interviews with the participants were made after their agreement. Results: The researcher classified the significant statements under 6 theme clusters, 1) sense of difference; 2) worries about health; 3) draining of emotion; 4) anxiety; 5) sadness; and 6) being comfortable. Conclusions: Shift work which is inevitable in modern society may have severe influences on shift workers' physical, mental and psychological aspects by causing their work cycle rhythm to be unbalanced. Finally, the researcher hopes that the results of the study would help understand workers' life and increase social concern and support to the workers.

• Korean Journal of Occupational Health Nursing
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• v.17 no.1
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• pp.45-54
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• 2008

Purpose: This study was conducted to compare and estimate sleep patterns and health status of the shift and non-shift factory workers. Methods: The subjects of this study were 290 male workers in 13 companies, which manufacture automobile parts in Daegu, Korea. Survey data were collected from March 5th, 2007 to April 5th, 2007. PSQI was scored to check the quality of sleep, ESS for excessive daytime sleep disorder, ISI for insomnia, and SF-36 for health status. The data were analyzed by $X^2$ and t-test using SPSS 12.0 for windows. Results: There was a difference in quality of sleep patterns between shift and non-shift workers (p=.033). A difference in the pattern of excessive daytime sleep (P=.005) and in the degree of insomnia (p=.030) were observed between the two groups. However, there were no significant difference in health status between the two groups. Conclusion: Based on these results, shift workers are in need of careful and continuous monitoring regarding sleep disorders and we need to develop health promotion programs including sleep hygiene for shift workers.

• Journal of Korean Academy of Nursing
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• v.24 no.2
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• pp.175-189
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• 1994

This study examined the daily rhythmic patterns of mood in shift workers. Ten rotating shift nurses (shift worker group) were matched with ten non-rotating student nurses (non - shift worker group) working under the same conditions at University Hospital. The subjects completed the Mood Adjective Checkist (MAC) every two or three hours from 6AM to 9-11 PM for six consecutive days. The MAC was constructed by Mansour and conversed the mood factors of Anger - Depression. Happiness, Mental, and Social. These data were analyzed by using Cosinor method. The results are summarized as follows : 1. There was no difference in mean scores for Anger - Depression, Happiness, Mental, and Social mood rhythm between the shift workers and the non - shift workers. 2. There was no difference in the amplitude of Anger - Depression, Happiness and Social mood between the two groups, but the shift workers had a higher amplitude of Mental mood. 3. The acrophases of the Anger - Depression mood were between 1:28 and 2:05, and those of Happiness, Social, and Mental mood were between 12:5 and 15:03 for both groups. There were no differences between the groups. 4. The number of the subjects with statistically significant mean cosinor rhythms for Anger-De-pression and Mental moods were higher in the shift workers than in the non-shift workers, but there were no differences between the shift workers and the non-shift workers in those of Happiness and Mental mood. This study showed that the mod manifested circadian periodicities, and a rapidly rotating shift system did not changed the circadian rhythm of mood. It is expected that this study will facilitate a better understanding of circadian rhythm in mood in the shiftworkers.