The association between Korean employed workers' on-call work and health problems, injuries

BACKGROUND: On-call work is a form of work that requires the person to work at any time during the on-call period. Thus, on-call work is often regarded as one of the most severe stress factors. This study investigates the associations between on-call work and health problems, injuries. METHODS: This study was based on the 3rd Korean Working Conditions Survey. Total of 29,246 employed workers who had been working for at least 1 year were included. Logistic regression analysis was performed to investigate the association between on-call work and health problems, injuries. RESULTS: The odds ratios for on-call workers in terms of physical health problems, psychological health problems, and injuries were 1.33 (95% confidence interval [CI] 1.22-1.44), 1.31 (95% CI 1.08-1.60), and 2.76 (95% CI 2.26-3.37), respectively. Analysis of the detailed symptoms revealed odds ratios in on-call workers of 2.06 for hearing problems (95% CI 1.63-2.62); 1.71 for skin problems (95% CI 1.38-2.12); 1.22 for back pain (95% CI 1.08-1.38); 1.23 for muscular pains in upper limbs (95% CI 1.12-1.34); 1.27 for muscular pains in lower limbs (95% CI 1.15-1.40); 1.46 for headache, eye fatigue (95% CI 1.32-1.60); 1.37 for abdominal pain (95% CI 1.02-1.85); 1.43 for depression or anxiety disorders (95% CI 1.07-1.93); 1.36 for fatigue (95% CI 1.24-1.49); and 1.41 for insomnia and general sleep difficulties (95% CI 1.13-1.76). CONCLUSIONS: The present study found that on-call work results in an increased risk of health problems and injuries. This study is the result of analyses of broad range of the job spectrum in Korean employed workers; thus, future studies are necessary to determine the effects of on-call work in various job groups.

Relationship between simultaneous exposure to ergonomic risk factors and work-related lower back pain: a cross-sectional study based on the fourth Korean working conditions survey

BACKGROUND: It is well known that ergonomic risk factors and back pain are related. However, few studies have examined the relationship between simultaneous exposure to these risk factors and back pain in a Korean population. We aimed to investigate the relationship between simultaneous exposure to ergonomic risk factors and work-related lower back pain (LBP) based on the fourth Korean Working Conditions Survey (KWCS). METHOD: The fourth KWCS (2014) was used for this study. Chi-square tests and logistic regression were used to assess relationship between 5 ergonomic risk factors and work-related LBP. We also analyzed the relationship between simultaneous exposure to 2 risk factors and work-related LBP. RESULTS: All 5 ergonomic risk factors (fatigue-inducing and painful posture; lifting or moving people; dragging, pushing, or moving heavy objects; standing posture; and repetitive hand or arm movements) were significantly correlated with work-related LBP in the severe exposure group (adjusted odd ratios [aOR] 5.09, 95% confidence interval [CI] 4.46–5.83; aOR 1.98, 95% CI 1.62–2.42; aOR 2.09, 95% CI 1.82–2.40; aOR 1.79, 95% CI 1.60–2.01; aOR 2.04, 95% CI 1.82–2.30, respectively). When exposed to 2 risk factors simultaneously, the relationship between exposure and work-related LBP was not greater than exposure to only 1 risk factor in our study (usually exposed to ‘fatigue-inducing or painful posture’ aOR 2.17, 95% CI 2.02–2.34; high exposure to both ‘fatigue-inducing or painful posture’ and ‘dragging, pushing, or moving heavy objects’ aOR 2.00, 95% CI 1.82–2.20). CONCLUSIONS: There was a strong relationship between severe exposure to each ergonomic risk factor and work-related LBP. However, when exposed to 2 ergonomic risk factors simultaneously, the relationship between exposure and work-related LBP was not stronger than when exposed to only 1 risk factor in our study.

The association between long working hours and work-related musculoskeletal symptoms of Korean wage workers: data from the fourth Korean working conditions survey (a cross-sectional study)

BACKGROUND: It has been reported that long working hours are hazardous to the workers’ health. Especially, work-related musculoskeletal disorders (WMSDs) have been considered as one of the significant health issues in workplace. The objective of this study was to identify the association between long working hours and work-related musculoskeletal symptoms. METHODS: The analysis was conducted using data from the Fourth Korean Working Conditions Survey (KWCS). Subjects of this study were 24,783 wage workers and divided into three groups according to the weekly working hours, which were ≤ 40, 41–52 and > 52 h. The relationship between long working hours and work-related musculoskeletal symptoms was analyzed by multivariate logistic regression method after adjusting for general, occupational characteristics including specific working motions or postures and psychosocial factors. RESULTS: Approximately 18.4% of subjects worked more than 52 h per week and 26.4 and 16.4% of male subjects and 33.0 and 23.4% of female subjects experienced work-related upper and lower limb pains, respectively, over the last 12 months. Moreover, the prevalence of upper and lower limb pain was increased in both genders as the weekly working hours increased. The odds ratios (ORs) of upper limb pain for those working 41–52 h and more than 52 h per week when adjusted for general, occupational characteristics including specific motions or postures and psychosocial factors were 1.36 and 1.40 for male workers and 1.26 and 1.66 for female workers compared to the reference group, respectively. Furthermore, ORs of lower limb pain for the same weekly working hour groups were 1.26 and 1.47 for male workers and 1.20 and 1.47 for female workers, respectively. CONCLUSIONS: Long working hours were significantly related to work-related musculoskeletal symptoms in Korean wage workers and appropriate interventions should be implemented to reduce long working hours that can negatively affect workers’ health.

The Relationship Between Frequency of Injuries and Workplace Environment in Korea: Focus on Shift Work and Workplace Environmental Factors☆

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.

Association between supervisors' behavior and wage workers' job stress in Korea: analysis of the fourth Korean working conditions survey

BACKGROUND: In modern society, many workers are stressed. Supervisors' support or behavior can affect the emotional or psychological part of the worker. The purpose of this study is to investigate the effect of supervisor's behavior on worker's stress. METHODS: The study included 19,272 subjects following the assignment of weighted values to workers other than soldiers using data from the Fourth Korean Working Condition Survey. Supervisors' behavior was measured using 5 items: “supervisor feedback regarding work,”“respectful attitude,”“good conflict-resolution ability,”“good work-related planning and organizational ability,” and the encouragement of participation in important decision making. Job stress was measured using 1 item: “I experience stress at work.” Multiple logistic regression analysis was performed to examine the effects of supervisors' behavioral, general, occupational, and psychosocial characteristics on job stress in workers. Organizational characteristics associated with supervisors' behavior were also analyzed. RESULTS: The results showed that supervisors' provision of feedback regarding work increased workers' job stress (OR = 1.329, 95% CI = 1.203 ~ 1.468). When a supervisor respect workers (OR = 0.812, 95% CI = 0.722 ~ 0.913) or good at planning and organizing works (OR = 0.816, 95% CI: 0.732 ~ 0.910), workers' job stress decreased. In particular, the two types of supervisor behaviors, other than feedback regarding work, were high in private-sector organizations employing less than 300 employees. CONCLUSION: Supervisors' behavior influenced job stress levels in workers. Therefore, it is necessary to increase education regarding the effects of supervisors' behavior on job stress, which should initially be provided in private-sector organizations with up to 300 employees.

The association between perceived discriminations and well-being in Korean employed workers: the 4th Korean working conditions survey

BACKGROUND: Around the globe, discrimination has emerged as a social issue requiring serious consideration. From the perspective of public health, the impact of discrimination on the health of affected individuals is a subject of great importance. On the other hand, subjective well-being is a key indicator of an individual's physical, mental, and social health. The present study aims to analyze the relationship between Korean employed workers' subjective health and their exposure to perceived discrimination. METHODS: The Fourth Korean Working Conditions Survey (KWCS, 2014) was conducted on a representative sample of the economically active population aged 15 years or older, who were either employees or self-employed at the time of interview. After removing inconsistent data, 32,984 employed workers were examined in this study. The data included general and occupational characteristics, perceived discrimination, and well-being. Well-being was measured through the WHO-Five index (1998 version). Multiple logistic regression analysis was used to examine the association between perceived discrimination and well-being. RESULT: As a group, employed workers who were exposed to discrimination had a significantly higher likelihood of “poor well-being” than their counterparts who were not exposed to discrimination. More specifically, the workers exposed to age discrimination had an odds ratio(OR) of 1.51 (95% CI: 1.36–1.68), workers exposed to discrimination based on educational attainment had an OR of 1.43 (95% CI: 1.26–1.61), and workers exposed to discrimination based on employment type had an OR of 1.68 (95% CI: 1.48–1.91) with respect to poor well-being. Furthermore, workers exposed to a greater number of discriminatory incidents were also at a higher risk of “poor well-being” than their counterparts who were exposed to fewer such incidents. More specifically, the workers with three exposures to discrimination had an OR of 2.60 (95% CI: 1.92–3.53), the workers with two such exposures had an OR of 1.69 (95% CI: 1.44–1.99), and the workers with one such exposure had an OR of 1.32 (95% CI: 1.20–1.45). CONCLUSION: The present study found that discrimination based on age, educational attainment, or employment type put workers at a higher risk of “poor well-being,” and that the greater the exposure to discrimination, the higher the risk of poor well-being.

Association between employment status and self-rated health: Korean working conditions survey

BACKGROUND: This research was conducted with an aim of determining the association between employment status and self-rated health. METHODS: Using the data from the Third Korean Working Conditions Survey conducted in 2011, We included data from 34,783 respondents, excluding employers, self-employed workers, unpaid family workers, others. Self-rated health was compared according to employment status and a logistic regression analysis was performed. RESULTS: Among the 34,783 workers, the number of permanent and non-permanent workers was 27,564 (79.2 %) and 7,219 (20.8 %). The risk that the self-rated health of non-permanent workers was poor was 1.20 times higher when both socio-demographic factors, work environment and work hazards were corrected. CONCLUSIONS: In this study, perceived health was found to be worse in the non-permanent workers than permanent workers. Additional research should investigate whether other factors mediate the relationship between employment status and perceived health.

The association between Korean workers’ presenteeism and psychosocial factors within workplaces

BACKGROUND: Presenteeism, a concept that has recently undergone active study, is the act of attending work while sick. This study investigates the association between presenteeism and various psychosocial factors within workplaces. METHODS: This study analyzed 29246 wage earners from the third Korean Working Conditions Survey (KWCS, 2011) data using the logistic regression analysis to investigate the association between presenteeism and various psychosocial factors within workplaces. RESULTS: Among the 29246 wage earners, 6347 (21.7 %) showed presenteeism. Those who experienced age discrimination at work (adjusted odds ratio (aOR) 1.77: 95 % CI 1.56–2.00), educational background discrimination (aOR 1.35: 95 % CI 1.22–1.51), regional discrimination (aOR 1.55: 95 % CI 1.31–1.83), sexual discrimination (aOR 1.65: 95 % CI 1.41–1.94), employment type discrimination (aOR 2.13: 95 % CI 1.89–2.40), physical violence (aOR 1.92: 95 % CI 1.45–2.55), sexual harassment (aOR 2.90: 95 % CI 2.01–4.19), job insecurity (aOR 1.36: 95 % CI 1.18–1.56), work–life imbalance (aOR 1.38: 95 % CI 1.29–1.47), low job satisfaction (aOR 2.04: 95 % CI 1.91–2.17), no colleague support (aOR 1.11: 95 % CI 1.02–1.21), job stress (aOR 1.89: 95 % CI 1.76–2.02), emotional labor (aOR 1.50: 95 % CI 1.41–1.60), high work intensity (aOR 1.31: 95 % CI 1.23–1.38), and 3 groups of job strain that are passive group (aOR 1.09: 95 % CI 1.00–1.18), active group (aOR 1.39: 95 % CI 1.28–1.51), and high strain group (aOR 1.35: 95 % CI 1.24–1.46) showed an increased risk of presenteeism compared to their respective counterparts (p < 0.01). CONCLUSIONS: The study results confirmed the association between presenteeism and various psychosocial factors within workplaces. Considering that presenteeism negatively affects productivity and the mental and physical health of individuals, managing various psychosocial factors within workplaces is proposed to reduce presenteeism.

Relationship of workplace violence and perpetrators on sleep disturbance-data from the 4th Korean working conditions survey

OBJECTIVE: The present study analyzed relationship of workplace violence and perpetrators of violence on sleep disturbance among wage workers in Korea. METHODS: The present study used data from the 4th Korean Working Conditions Survey (KWCS) of 2014 in selecting a total of 25,138wage workers as the study population, which excluded those who failed or refused to respond to questions required for the present study. The workplace violence experience group included people who satisfied at least one of six relevant criteria (verbal abuse, unwanted sexual attention, threatening or humiliating behavior, physical violence, bullying/harassment, and sexual harassment) and the group was divided according to whether the perpetrator of violence was a client or colleague. Presence of sleep disturbance was determined based on subjective symptoms felt within the past 12 months by each individual. A multiple logistic regression analysis was performed to identify the effects on sleep distance according to general, occupational, and psychosocial characteristics, as well as the types of workplace violence and perpetrators of violence. RESULTS: Workplace violence was found as a factor affecting sleep disturbance (OR = 3.773, 95 % CI = 3.058–4.655), and with respect to perpetrators of violence, complaint of sleep disturbance symptoms was higher when the perpetrator was a colleague or boss (OR = 5.688, 95 % CI 4.189–7.723) than a client (OR = 2.992, 95 % CI 2.301–3.890). CONCLUSION: Workplace violence had an effect on occurrence of sleep disturbance and when the perpetrators of violence was a boss or colleague at work, the risk for symptoms such as sleep disturbance increased, which indicated the need for appropriate intervention from a workplace healthcare perspective, including preventive education of workplace violence among employees.

Association between night work and cardiovascular diseases: analysis of the 3rd Korean working conditions survey

OBJECTIVES: This study was conducted to investigate the relationship between night work and cardiovascular diseases among wage workers in Korea. METHODS: The study was based on the 3rd Korean Working Conditions Survey (KWCS; 2011). This study included 29,711 wage workers. We used the chi-squared test and logistic regression to examine the association between cardiovascular diseases and night work and cumulative night work. RESULTS: Among all of the paid workers, 12.5% reported doing night work > or = 1 day per month. Night work was significantly associated with an increased risk of cardiovascular diseases (odds ratio [OR] 1.58, 95% confidence interval [CI] 1.11-2.25). Also, compared to the group that did not do night works, the group with higher cumulative night work demonstrated an increased risk for cardiovascular diseases (OR 1.81, 95% CI 1.19-2.74). CONCLUSIONS: This study suggests that night work is significantly associated with cardiovascular diseases.

The Type of Payment and Working Conditions

BACKGROUND: The type of payment is one of the important factors that has an effect on the health of employees, as a basic working condition. In the conventional research field of occupational safety and health, only the physical, chemical, biological, and ergonomic factors are treated as the main hazardous factors. Managerial factors and basic working conditions such as working hours and the type of payment are neglected. This paper aimed to investigate the association of the type of payment and the exposure to the various hazardous factors as an heuristic study. METHODS: The third Korean Working Conditions Survey (KWCS) by the Occupational Safety and Health Research Institute in 2011 was used for this study. Among the total sample of 50,032 economically active persons, 34,788 employees were considered for analysis. This study examined the relation between the three types of payment such as basic fixed salary and wage, piece rate, and extra payment for bad and dangerous working conditions and exposure to hazardous factors like vibration, noise, temperature, chemical contact, and working at very high speeds. Multivariate regression analysis was used to measure the effect of the type of payment on working hours exposed to hazards. RESULTS: The result showed that the proportion of employees with a basic fixed salary was 94.5%, the proportion with piece rates was 38.6%, and the proportion who received extra payment for hazardous working conditions was 11.7%. CONCLUSION: The piece rate was associated with exposure to working with tight deadlines and stressful jobs. This study had some limitations because KWCS was a cross-sectional survey.

Korean Emotional Laborers' Job Stressors and Relievers: Focus on Work Conditions and Emotional Labor Properties

BACKGROUND: The present study aims to investigate job stressors and stress relievers for Korean emotional laborers, specifically focusing on the effects of work conditions and emotional labor properties. Emotional laborers are asked to hide or distort their real emotions in their interaction with clients. They are exposed to high levels of stress in the emotional labor process, which leads to serious mental health risks including burnout, depression, and even suicide impulse. Exploring job stressors and relieving factors would be the first step in seeking alternatives to protect emotional laborers from those mental health risks. METHODS: Using the third wave data of Korean Working Conditions Survey, logistic regression analysis was conducted for two purposes: to examine the relations of emotional labor and stress, and to find out job stressors and relievers for emotional laborers. RESULTS: The chances of stress arousal are 3.5 times higher for emotional laborers; emotional laborers experience double risk-burden for stress arousal. In addition to general job stressors, emotional laborers need to bear burdens related to emotional labor properties. The effect of social support at the workplace is not significant for stress relief, unlike common assumptions, whereas subjective satisfaction (wage satisfaction and work-life balance) is proven to have relieving effects on emotional laborers' job stress. CONCLUSION: From the results, the importance of a balanced understanding of emotional labor for establishing effective policies for emotional laborer protection is stressed.

Presenteeism among self-employed workers: Korean working conditions survey

OBJECTIVE: Presenteeism has become a public concern recently. Thus, we aimed to understand the relationship between self-employed workers and presenteeism using a nationally representative sample of Korean workers. METHODS: Using data from the Korean Working Conditions Survey conducted in 2011, a total of 43,392 workers including paid employees and self-employed workers were analyzed. The effect of employment status on presenteeism was analyzed using logistic regression analysis. The independent variables were socioeconomic characteristics, working conditions, and working environments. RESULTS: Among the 43,392 workers, 34,783 were paid and 8,609 were self-employed. Self-employed workers were more likely to exhibit presenteeism than were paid workers. An elevated odds ratio of 1.27 (95% CI 1.19-1.36) was found for presenteeism among self-employed workers. CONCLUSION: Being self-employed was significantly related with exhibiting presenteeism. Additional research should investigate whether other factors mediate the relationship between employment status and presenteeism as well as ways to reduce presenteeism among self-employed workers.

Association between Workplace Risk Factor Exposure and Sleep Disturbance: Analysis of the 2nd Korean Working Conditions Survey

OBJECTIVES: Sleep is essential for human beings to live and work properly. This study was conducted to investigate the relationship between occupational exposures to workplace risk factors and sleep disturbance in Korean workers. METHODS: The data were drawn from the second Korean Working Conditions Survey (KWCS); a total of 7,112 paid workers were analyzed. The independent variables were occupational exposures such as physical, chemical, biological, and psychosocial risk factor in the workplace, and psychosocial risk factor was divided into five categories (job demand, job control, social support, job insecurity, lack of reward). We estimated the relationship between various occupational exposures and sleep disturbance using multivariate logistic regression analysis. RESULTS: The results showed that people who exposed to physical, chemical, biological, and psychosocial (high job demand, inadequate social support, lack of reward) risk factors were more likely to increase the risk of sleep disturbance. Furthermore, after adjusting for general and occupational characteristics, we found significant positive associations between exposures to physical (odds ratios [OR] 1.47, 95% confidence interval [CI] 1.05-2.07) and psychosocial (high job demand (OR 2.93, 95% CI 2.16-3.98), inadequate social support (OR 1.57, 95% CI 1.14-2.15), lack of reward (OR 1.45, 95% CI 1.08-1.96)) risk factors and sleep disturbance. CONCLUSION: These results suggest that occupational exposures to physical and psychosocial workplace risk factors are significantly related to sleep disturbance.

Association between work-related health problems and job insecurity in permanent and temporary employees

OBJECTIVES: This research was conducted with an aim of determining the correlation between job insecurity and an employee's work-related health problems among permanent and temporary workers. METHODS: Using the data from the First Korean Working Conditions Survey conducted in 2006, a total of 7,071 workers, excluding employers and the self-employed, were analyzed. Work-related health problems were categorized as backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety or depression. Each problem was then analyzed for its relationship to job insecurity through logistic regression analysis. RESULTS: Among the 7,071 workers, 5,294 (74.9%) were permanent workers and 1,777 (25.1%) were temporary workers. For the permanent workers, presence of high or moderate job insecurity appeared more closely linked to backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety, and depression compared to absence of job insecurity. However, for the temporary workers, only depression appeared to be associated with the presence of high job insecurity. CONCLUSION: The study showed that the presence of job insecurity is correlated with work-related health problems. The deleterious effects of job insecurity appeared to be stronger in permanent than temporary workers. Additional research should investigate ways to effectively reduce job insecurity.

The Validity and Reliability of the Second Korean Working Conditions Survey

BACKGROUND: The aim of this study was to evaluate the quality of the Second Korean Working Conditions Survey (KWCS), focusing on its validity and reliability. METHODS: The external validity was evaluated by the assessment of sampling procedures and the response rate, in order to investigate the representativeness of the sample. The content validity was evaluated by the assessment of the development of the questionnaire, and the consistency of questions for the selected construct. The test-retest method was used to evaluate the reliability by means of a phone call survey of 30% of the respondents, who were randomly selected. The respondents' satisfaction regarding the survey procedures and interview time were analyzed to evaluate the quality of survey data. RESULTS: The external validity was assured by an acceptable sampling procedure, rigid multi-stage stratified cluster random sampling. The content validity was also guaranteed by a reasonable procedure for the development of the questionnaire with a pretest. The internal consistency of the questions for work autonomy was maintained, with 0.738 of Cronbach's alpha. The response rate of 36% was lower than that of the European Working Conditions Survey (EWCS), with a contact rate of 66%, compared to 76% for the EWCS. The matching rates of the five retested questions were more than 98% reliable. CONCLUSION: The quality of the second KWCS was assured by the high external and content validity and reliability. The rigid sampling procedure and development of the questionnaire contributed to quality assurance. The high level of reliability may be guaranteed by the sophisticated field survey procedures and the development of a technical manual for interviewers. The technical strategies for a high response rate should be developed for future surveys.

The Relationship between Shift Work and Work-related Injuries among Korean Workers / 대한산업의학회지

OBJECTIVES: The aim of this study was to evaluate the relationship between shift work and work-related injuries in a representative sample of Korean workers. METHODS: We used data from the Korean Working Condition Survey of 2006. The participants were 7,075 Korean workers 15 to 64 years of age. Logistic regression was employed to estimate the relationship between shift work and work-related injury using the SAS version 9.2 program. RESULTS: Shift work was significantly related to work-related injuries compared to non-shift workers(OR 2.40, 95% CI=1.65~3.48). When personal and occupational risk factors were accounted for, shift work had a statistically meaningful relationship with work-related injuries compared to non-shift work(OR 1.79, 95% CI=1.20~2.66). CONCLUSIONS: In this study, shift workers appear to have a higher risk of work-related injuries compared to non-shift workers. Work-related injuries in shift workers could be attributed to circadian rhythm disorder and sleep problems. Suitable arrangements that ensure flexible working times are needed for shift workers. Further study will be needed to identify and mitigate work-related injuries among shift workers.