The Modified International Standard Classification of Occupations defined by the clustering of occupational characteristics in the Korean Working Conditions Survey

Beyond working hours: the association between long working hours, the use of work-related communication devices outside regular working hours, and anxiety symptoms

OBJECTIVES

The present study aimed to identify and compare the associations between long working hours and use of work-related communication devices outside regular working hours and anxiety symptoms, thereby providing insight into redefining working hours.

METHODS

Based on the cross-sectional data from the sixth Korean Working Conditions Survey (KWCS), specifically the responses from 46 055 workers, the use of work-related communication devices outside of regular working hours, long working hours, and anxiety symptoms were assessed. To investigate the associations between using work-related communication devices outside regular working hours or long working hours with anxiety symptoms, odds ratios (ORs) and 95% CIs were calculated using multiple logistic regression models.

RESULTS

Among 46 055 participants, 25 659 (55.7%) used work-related communication devices outside working hours, 8145 (17.7%) worked long hours, and 2664 (5.8%) experienced anxiety symptoms. Compared with the reference group, those who used work-related communication devices outside regular working hours without working long hours, had higher OR of anxiety symptoms (OR: 2.18; 95% CI, 1.97-2.41) than those who worked long hours without using work-related communication devices during off-hours (OR: 1.32; 95% CI, 1.09-1.59). Furthermore, the group that both worked long hours and used work-related communication devices outside working hours exhibited the highest OR of anxiety symptoms (OR: 2.57; 95% CI, 2.24-2.97).

CONCLUSIONS

Using work-related communication devices outside regular working hours is associated with a higher risk of anxiety symptoms compared with long working hours. This result suggests that using work-related devices outside regular working hours, in addition to regular work time, should be considered when redefining working hours.

Occupation-based demographic, clinical, and psychological presentation of spine pain: A retrospective analysis of 71,727 patients from urban India

BACKGROUND

Although many studies have investigated the physical and ergonomic risks of spine pain in specific occupation groups, the literature is lacking on occupation-based clinical and psychological presentation in patients with spine pain.

OBJECTIVE

To analyze occupation-based variation in demographic, clinical, and psychological presentation in patients with spine pain.

METHODS

This retrospective study analyzed the clinical data of 71727 patients with spine pain visiting a chain of spine rehabilitation clinics. Demographic and clinical variables such as gender, age, affected site, symptom duration, clinical symptoms and presentation, pain intensity, disability, and STarT Back Screening Tool (SBT) risk were compared between 9 occupational groups.

RESULTS

The service and sales workers (44%) and students (43.5%) groups had the highest percentage of patients who presented with central spine pain; military personnel had the highest percentage of patients who presented with unilateral radicular pain (51.5%); and the retired or unemployed group had the highest percentage of patients who presented with severe myotomal loss (grade≤3) (6%). Homemakers had significantly higher pain intensity and disability (p < 0.001) and had the highest percentage of patients who presented with severe pain (47%), severe and crippled disability (59.5%), and medium to high risk (59%) with SBT when compared to other occupational groups.

CONCLUSION

Patients with spine pain showed variation in demographic, clinical, and psychological presentation based on their occupation. The findings of this study can be the basis for identifying risk factors for spine pain and helping plan preventive and treatment measures based on their occupation.

Increased risk of sleep problems according to employment precariousness among paid employees in Korea

BACKGROUND

This study aimed to investigate the relationship between precarious employment (PE) and sleep problems among wage workers in Korea.

METHODS

Data from 29,437 wage workers were obtained from the 6th Korean Working Conditions Survey. PE was defined based on four dimensions: employment temporariness, irregularity, lack of protection, and economic vulnerability. A PE index indicating employment precariousness was derived. The outcome variables were three sleep problems experienced over the past year: difficulty initiating asleep; difficulty maintaining sleep' and fatigue upon waking. Multiple logistic regression was performed after adjusting for age, educational level, occupation, job tenure, company size, and working hours, to estimate the association between PE and sleep problems.

RESULTS

For both sexes, the risk of all sleep problems significantly increased as the precariousness of employment increased, showing a dose-response relationship.

CONCLUSION

An increased risk of sleep problems is evident as employment becomes more precarious. These findings could help improve the health of workers with PE by addressing sleep problems.

Association between unmet healthcare needs and suicidal behaviors among the Korean population

OBJECTIVE

Suicide is an important public health concern. In South Korea, suicide rates have steadily risen over the past two decades. Unfortunately, there is a dearth of literature on the effects of unmet healthcare needs on suicide. Therefore, this study aimed to analyze the relationship between unmet healthcare needs and suicidal behaviors (suicidal ideation, plans, and attempts).

METHOD

This study analyzed data from 27,498 participants assessed by the Korea National Health and Nutrition Examination Survey conducted between 2016 and 2020. Logistic regression was used to evaluate the relationship between unmet healthcare needs and suicidal behaviors, while controlling for age, sex, education, household income, occupation, smoking, obesity, and alcohol consumption.

RESULTS

Adjusted odds ratios (95% confidence interval) were significantly higher in participants who experienced unmet healthcare needs [suicidal ideation: 2.31 (1.84-2.90); suicidal planning: 2.23 (1.75-2.85); and suicidal attempts: 1.92 (1.27-2.87)]. After stratifying for sex and depression, this trend was maintained in male participants and those without a depression diagnosis.

CONCLUSIONS

This study analyzed the relationship between unmet healthcare needs and suicidal behavior. Further studies using data sources that include more detailed information on suicide and somatic symptoms are required.

Association between medication adherence to chronic diseases and shift-work schedules in the Korean working population

Shift-working schedules are closely linked to chronic diseases, and only a few studies have investigated the association between working schedules and medication adherence in chronic diseases targeting workers. This study aimed to investigate whether shift-work schedules are associated with medication adherence in a working population with chronic conditions. The study participants (n = 11,460 person-years) were identified from the Korea Health Panel Study conducted from 2008 to 2018. Medication adherence was classified as good (2+) or poor (0 or 1) based on the 4-item Morisky Medication Adherence Scale. Work schedules were categorized as shifts and fixed daytime work. Its association with medication adherence was investigated using a generalized estimating equation model, generating odds ratios (OR) with 95% confidence intervals (CI). According to work schedules, shift workers were more likely than fixed-day workers to have poor medication adherence (adjusted OR = 1.16, 95% CI: 1.02-1.33). Regarding occupational classification, manual workers had a significantly higher risk of poor medication adherence than those in other occupational categories (adjusted OR = 1.27, 95% CI: 1.13-1.43). Among shift workers, the major reason for poor medication adherence was forgetting to take medication (SPR = 1.23, 95% CI: 1.07-1.38). Workers with irregular shift times are more vulnerable to poor medication adherence. Future studies are required to understand the mechanisms underlying this association and develop strategies to enhance medication adherence in the working population.

Status of Workers' Health Behavior and the Association between Occupational Characteristics and Health Behavior

This study investigated differences in unhealthy lifestyle behaviors (ULBs) between workers and nonworkers and demonstrated the association of ULBs with occupational characteristics among workers. This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey from 2007 to 2019. For sociodemographic data, chi-squared tests were used to analyze categorical variables. Odds ratios (ORs) and 95% confidence intervals (CIs) for ULBs were estimated using Poisson regression models after adjusting for age, sex, educational level, and household income. The variables used were current smoking status, heavy drinking, and physical inactivity. Workers were associated with an increased risk of current smoking (adjusted OR (aOR) = 1.48, 95%CI = 1.41-1.56), heavy drinking (aOR = 1.79, 95%CI = 1.68-1.90), and physical inactivity (aOR = 1.07, 95%CI = 1.04-1.11) compared with nonworkers. Among workers, the differential risks of ULB according to occupational characteristics were as follows: skilled manual workers, self-employed workers, and workers working >40 h/week were at a higher risk of engaging in all ULBs than those in other occupational categories, paid workers, and workers working ≤40 h/week, respectively. Workers showed a higher risk of ULBs than nonworkers. The risk of ULBs differed according to occupational characteristics, highlighting the need for additional studies and detailed occupational health management.

Status and Risk of Noncompliance of Adherence to Medications for Metabolic Diseases According to Occupational Characteristics

Thus far, little attention has been paid to adherence to medications focusing on the workers and occupational characteristics. This study aimed to assess the status and risk of noncompliance among workers compared to nonworkers, and the association between nonadherence to medication of metabolic diseases and occupational characteristics. Self-reported adherence to medications for hypertension, diabetes, or dyslipidemia and occupational characteristics were evaluated using the Korea Health Panel Study (2008-2018). The status of adherence to medications was evaluated based on working status, with detailed reasons provided for noncompliance. The risk of noncompliance was estimated using the generalized estimating equation, and a subgroup analysis with age-standardized prevalence ratio according to occupational characteristics was also conducted. During the follow-up period, 19,660 (13.9%) person years were noncompliant with medication adherence for 141,807 person years. Workers had a higher prevalence (15.0%) of noncompliance than nonworkers (13.0%). Workers (OR:1.10, 95% CI:1.04-1.14) showed an increased risk of noncompliance compared to nonworkers. Workers who were manual, unpaid family workers, irregular, or dispatched workers showed an increased prevalence of noncompliance. This study found that workers were susceptible to nonadherence to metabolic disease medication. Future research on the role of working conditions in medication adherence would benefit metabolic disease prevention.

The relationship between domain-specific physical activity and depressive symptoms in Korean adults: Analysis of the Korea National Health and Nutrition Examination Survey

BACKGROUND

This study aimed to investigate the associations of domain-specific physical activity (PA) with the prevalence of depressive symptoms.

METHODS

We analyzed data from 11,679 (5,056 men and 6,623 women) participants aged ³19 years in the Korea National Health and Nutrition Examination Survey (2016 and 2018 waves). Depressive symptoms were measured using the Korean version of the Patient Health Questionnaire-9 (PHQ-9), with a cut-off score for depression of 11. The participants were first categorized by sex, and then by their PA level in different PA domains into three different groups. We examined the correlations between domain-specific PA and depressive symptoms using logistic regression analysis after controlling for confounders.

RESULTS

Total amount of PA was not associated with depressive symptoms. However, in both sexes, those high in leisure and transport PA had lower levels of depressive symptoms compared with those with no leisure and transport PA (p for trend <0.001). After adjusting for covariates, those high in work PA showed a significantly higher likelihood of having depressive symptoms both in male (OR= 2.74, 95% CI 1.56-4.82) and female participants (OR= 2.84, 95% CI 1.70-4.49), compared to those with no work PA.

LIMITATION

Cross-sectional nature of the data prevents causal associations.

CONCLUSIONS

Although the total amount of PA participation was not associated with depressive symptoms, domain-specific PAs were differently associated with depressive symptoms. Specifically, higher amount of work PA was significantly associated with higher prevalence of depressive symptoms; this topic deserves further attention and future investigation.

Comparative analyses of occupational injuries among temporary agency worker and direct contract workers: Findings from the Korea Health Panel 2009-2018

Objectives

Several studies have reported health or safety risk of temporary agency workers (TAW). Since most of the studies are just cross‐sectional studies, we intended to identify the risk of occupational injury in TAW, using longitudinal study design.

Methods

The Korea Health Panel 2009–2018 data were used in the study. For the statistical analysis of this study, we used a panel logit model to identify the risk of occupational injury in TAW compared to direct contract workers (DCW).

Results

There was no significant difference in risk of occupational injury between TAW and DCW among the overall population (adjusted OR 0.920, 95% CI 0.600–1.411). However, there was a significant increase in occupational injury in women (adjusted OR 2.134, 95% CI 1.092–4.170) and the “19–34” age group (adjusted OR 2.744, 95% CI 1.103–6.825) of TAW.

Conclusions

This study provides evidence for vulnerable groups such as women and younger age groups in the relationship between TAW and occupational injury.

The Effect of Change of Working Schedule on Health Behaviors: Evidence from the Korea Labor and Income Panel Study (2005–2019)

This study investigated whether changes in work schedule are associated with health behavior changes. We used data from the Korea Labor and Income Panel Survey from 2005 to 2019. A generalized estimating equation model was used to assess the association between changes of work schedules (day–day, day–shift, shift–day, and shift–shift) and health behaviors. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated after adjusting for general and socioeconomic characteristics. Fixed daytime work was observed for 25,716 person-years, and fixed shift work was observed for 2370 person-years out of the total 4046 participants during a 14 year period. Workers who changed their work schedule from fixed daytime to shift work and from shift to fixed daytime work contributed to 670 and 739 person-years, respectively. Considering continuous fixed daytime workers as a reference group, continuous exposure to shift work (aOR 1.11, CI 1.01–1.26) and changes from fixed daytime to shift work (aOR 1.18, CI 1.05–1.44) were significantly associated with an increased risk of changing either smoking or drinking behavior to unhealthy patterns. The results of our study suggest that workers who work irregular shift times, in contrast to those with more standard, regular work schedules, are at a higher risk of changing smoking and/or drinking behavior to unhealthy patterns.

The combined effect of long working hours and individual risk factors on cardiovascular disease: An interaction analysis

Objectives

We examined whether the effect of long working hours on the risk of developing cardiovascular disease (CVD) differs depending on individual risk factors.

Methods

Seven‐year follow‐up data were extracted from the 2009 to 2016 waves of the Korea Health Panel Survey. Physician's diagnosis or medication for hypertension, diabetes, dyslipidemia, and obesity were included as chronic disease status. Smoking, drinking alcohol, and exercise levels were considered as lifestyle behavior. Hazard ratios were calculated using the Cox regression models to evaluate the risk of CVD related to chronic diseases and unhealthy behavior, based on working hour groups, after adjusting for other covariates. The interactive effects of long working hours with or without chronic diseases and unhealthy behavior on CVD were assessed using the relative excess risk due to interaction and attributable proportion measures.

Results

There was a statistically significant interaction between long working hours and chronic diseases within the population, especially among male participants (P‐value for interaction <.01 and .03, respectively). There were no significant interactions between unhealthy behavior and long working hours.

Conclusions

Long working hours and chronic disease have a synergistic negative effect on the risk of CVD.

Associations Between Workplace Violence, Mental Health, and Physical Health among Korean Workers: The Fifth Korean Working Conditions Survey

BACKGROUND

Workplace violence (WPV) is a global public health problem and a threat to the health of Korean workers. This study assessed the prevalence and risk factors of WPV and its association with mental and physical health among Korean workers.

METHODS

Data obtained for 50,205 respondents to the Fifth Korean Working Conditions Survey were utilized for this study. Verbal abuse, threats, physical violence, and sexual harassment were assessed individually and as a composite for "any WPV." Workers were characterized by education, income, shift work status, access to a health and safety education program, work sector and overall health. Descriptive analyses and multiple logistic regression analyses were used to estimate the prevalence of WPV and its association with mental and physical health.

FINDINGS

Overall, 5.6% of workers reported experiencing one of four forms of WPV. The prevalence of verbal abuse, threats, physical violence, and sexual harassment were 4.9%, 0.7%, 0.2%, and 1.1%, respectively. Most perpetrators were customers. Prevalence of WPV was associated with lower education level, poor health status, long working hours, shift work, and no experience of health and safety education; 9.0% of service workers experienced violence. Workers who had experienced WPV were more likely to experience anxiety, sleep-related problems, depressive symptoms, back pain, headache/eye strain, and overall fatigue.

CONCLUSIONS/APPLICATIONS TO PRACTICE

Workplace violence is a serious occupational and public health concern in Korea. These results suggest managing WPV may improve workers' well-being and that violence-prevention strategies, policies, and regulations should be implemented across most industries.

Obesity and occupation in Thailand: using a Bayesian hierarchical model to obtain prevalence estimates from the National Health Examination Survey

BACKGROUND

Like many developing countries, Thailand has experienced a rapid rise in obesity, accompanied by a rapid change in occupational structure. It is plausible that these two trends are related, with movement into sedentary occupations leading to increases in obesity. National health examination survey data contains information on obesity and socioeconomic conditions that can help untangle the relationship, but analysis is challenging because of small sample sizes.

METHODS

This paper explores the relationship between occupation and obesity using data on 10,127 respondents aged 20-59 from the 2009 National Health Examination Survey. Obesity is measured using waist circumference. Modelling is carried out using an approach known as Multiple Regression with Post-Stratification (MRP). We use Bayesian hierarchical models to construct prevalence estimates disaggregated by age, sex, education, urban-rural residence, region, and occupation, and use census population weights to aggregate up. The Bayesian hierarchical model is designed to protect against overfitting and false discovery, which is particularly important in an exploratory study such as this one.

RESULTS

There is no clear relationship between the overall sedentary nature of occupations and obesity. Instead, obesity appears to vary occupation by occupation. For instance, women in professional occupations, and men who are agricultural or fishery workers, have relatively low rates of obesity.

CONCLUSION

Bayesian hierarchical models plus post-stratification offers new possibilities for using surveys to learn about complex health issues.

The Occupational Characteristics and Health Status of Workers in Geographically Isolated and Confined Areas in the Republic of Korea

BACKGROUND

This study investigates the safety and health status of geographically isolated and confined workers.

METHODS

This study was conducted in Baekryeong Island in Korea in 2020. The age-standardized prevalence ratios (aSPR) for occupational injury, unmet medical needs, psychological status, and lifestyle were estimated from the available data. Also, we compared the aSPRs of workers in Baekryeong Island with a reference study population who participated in a nationally representative survey in Korea.

RESULTS

The study revealed that Baekryeong Island workers had an increased risk of acquiring health and safety problems compared to the general worker population. The island workers showed a significant increase in unmet medical care (aSPR, 5.319; 95% confidence interval [CI], 3.984-6.958) and occupational injury (aSPR, 8.371; 95% CI, 3.820-15.892).

CONCLUSION

This study identified the safety and health problems of geographically isolated workers in Baekryeong Island. The risk of occupational injury and unmet medical care are simultaneously highlighted in the region's population, thereby underscoring the importance of prevention.

The Impact of Long Working Hours on Cognitive Function: A Follow-Up Study with Gender Stratification

BACKGROUND

Recent studies have shown that long working hours can have adverse consequences on health and possibly trigger biological processes that mediate the relationship between long working hours and cognitive decline.

OBJECTIVE

To investigate whether long working hours and the overall duration such exposure is associated with a decline in cognitive function.

METHODS

Data obtained during the Korean Longitudinal Study on Aging (n = 2,518) during the period 2006-2018 were used to explore the relationship between long working hours and cognitive decline. Korean version of the Mini-Mental State Examination (K-MMSE) scores were used to evaluate cognitive function. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), which were used to evaluate declines in K-MMSE scores over the 12-year study period.

RESULTS

Overall HR (95% CI) for a decline in cognitive function in long working hours group was 1.13 (0.73-1.17). When categorized by sex, women with long working hours had an HR (95% CI) of 1.50 (1.05-2.22), K-MMSE scores decreased significantly after working long hours for 5 years (p < 0.01).

CONCLUSION

The study furthers understanding of the effects of long working hours on cognitive decline among female workers. Further research is required to determine the effects of long working hours on cognitive functions.

Synergistic Effects and Sex Differences in Anthropometric Measures of Obesity and Elevated High-Sensitivity C-Reactive Protein Levels

Background: It remains unclear which anthropometric measure best predicts elevated high-sensitivity C-reactive protein (hs-CRP) levels. This study investigated the association and synergistic interaction of two obesity indices with elevated hs-CRP levels in a national sample of Korean adults, stratified by sex. Methods: The present cross-sectional study used data from the 2015–2018 Korea National Health and Nutrition Examination Survey of 18,610 subjects aged ≥20 years after excluding those with missing variables. Multiple logistic regression analyses and chi-squared tests were performed to investigate the association between body mass index (BMI) and waist circumference (WC) with elevated hs-CRP levels. Interaction analysis was used to examine the synergistic effect between BMI and WC on the risk of having elevated hs-CRP levels. Results: Elevated hs-CRP levels exceeding 3 mg/L were present in 9.3% and 7.5% of men and women, respectively. The relationship between each obesity index and elevated hs-CRP levels was significant in women (high WC (odds ratio [OR] = 1.77, 95% confidence interval [CI] = 1.24–2.54), high BMI (OR = 2.08, 95% CI = 1.58–2.74)) but not in men (high WC (OR = 1.19, 95% CI = 0.86–1.64), high BMI (OR = 0.99, 95% CI = 0.77–1.29)). Furthermore, combined measures of the two obesity indices and interaction analysis results revealed a synergistic association in men (OR = 1.57, 95% CI = 1.33–1.85; relative excess risk due to interaction (RERI) = 0.39, 95% CI = −0.09–0.86), and women (OR = 3.70, 95% CI = 3.09–4.43; RERI = 0.85, 95% CI = −0.06–1.75). Conclusion: BMI and WC were significantly associated with a risk of elevated hs-CRP levels in women but not in men. Nevertheless, significant synergistic interactions were seen in combined measures of BMI and WC, regardless of sex. These findings emphasize the need to use both measures of adiposity concurrently in the assessment of obesity and when identifying cardiovascular risk.

Impact of occupational dust exposure on dermatologic symptoms among Korean workers

Occupation-related dust exposure is common, especially with increased industrialization. While occupational dust-related health issues caused by inhalation or ingestion have been well studied, only a few studies have examined the dermatologic effects of occupational dust exposure. This study aimed to investigate the association between occupational dust exposure and dermatologic symptoms in Korean workers. Among the large-scale representative data from the fifth Korean Working Conditions Survey, 45,700 workers were selected for study. Occupational dust exposure level was categorized as none, moderate, and severe, and dermatologic symptoms were assessed using a questionnaire on health problems. We analyzed the association between occupational dust exposure and dermatologic symptoms using multivariate logistic regression. Risks of skin problems and work-related skin problems were significantly associated with the level of occupational dust exposure in a dose-dependent manner (odds ratio (95% confidence interval): moderate, 1.51 (1.14-2.01); severe, 2.39 (1.74-3.29) in general skin problems; moderate, 1.72 (1.22-2.42); severe, 3.06 (2.11-4.44) in work-related skin problems). We, thus, demonstrate an association between occupational dust exposure and skin problems. As skin absorption of dust is a major route of dust exposure at the workplace, it is necessary to determine the efficacy of continuous management of occupational dust exposure.

Working Conditions and Mental Health Status Related With Occupational Injury of Korean Outdoor Workers

OBJECTIVE

This study investigated the working conditions and mental health status linked to occupational injury among Korean outdoor workers.

METHODS

Socioeconomic and occupational characteristics were collected using self-reported questionnaires from 26,468 paid workers selected using the 5th Korean Working Conditions Survey. The relationships among mental health issues, occupational injury, and working outdoors were estimated by logistic regression.

RESULTS

Outdoor workers were relatively older with lower educational levels and income, worked longer, and had greater exposure to occupational hazards, higher occupational injury rate, significantly higher risk of sleep disturbances, and higher occupational injury rates due to sleep disturbances than non-outdoor workers.

CONCLUSIONS

There was a significant relationship among working outdoors, sleep quality, and mental health-related issues due to exposure to occupational hazards. Specific occupational health and safety strategies are needed to protect the mental health of outdoor workers.

Effect of work-related factors on the prevalence of peptic ulcer disease among Korean workers: a nationwide population-based study

BACKGROUND

Working environment such as psychosocial factors impacts the health of workers. However, few studies have assessed the association of work-related factors with the prevalence of peptic ulcer disease (PUD) in large population based study.

METHODS

After exclusion of military personnel, 16,099 wage workers (20 ≤ age ≤ 65 years) from the Fourth Korea National Health and Nutrition Examination Survey (2008-2011) were included in this study. Job status was defined as the place of employment of longest duration. To evaluate the working environment, we used a comprehensive work-stressor measure. Univariate and multivariable regression analyses were performed to assess the effect of occupation type on the prevalence of PUD.

RESULTS

Among the subjects, 5540, 3398, and 7161 were white-, pink-, and blue-collar workers, respectively. The prevalence of PUD was highest among blue-collar workers (n = 336, 7.1%), followed by pink-collar (n = 116, 5.1%) and white-collar (n = 180, 4.9%) workers. In the multivariable analysis, work type and uncomfortable gestures were independently associated with the risk of PUD. Compared with office workers, operators in industrial plants and machine operators had a significantly higher prevalence of PUD (odds ratio, 1.9; 95% confidence interval, 1.1-3.3) after adjusting for age, socioeconomic factors, sex, smoking, alcohol consumption, daily exercise, sleep duration, and working conditions.

DISCUSSION

In conclusion, work-related factors, particularly blue-collar work and uncomfortable job gestures, are independently associated with the risk of PUD. Therefore, it is important to monitor the development of PUD in workers exposed to these factors.

Association between Occupational Noise and Vibration Exposure and Insomnia among Workers in Korea

Background: The effect of noise and vibration exposure on disturbed sleep has been investigated in the past. However, this study was carried out to investigate the relationship between workplace noise and vibration exposure with insomnia amongst representative Korean workers, both simultaneously and separately. Methods: Our research analyzed an overall population of 30,837 workers aged 15 years or older using data derived from the 5th Korean Working Conditions Survey (KWCS) conducted in 2017. Chi-squared tests and logistic regression were performed to investigate baseline characteristics and to quantify the association between workplace exposure to noise and vibration with insomnia. Relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (S) were calculated to measure interactions between simultaneous noise and vibration exposure with insomnia. Results: The prevalence of those who reported insomnia was 18.3% of the general population. Among men and women, insomnia in those who were exposed to noise only was 13.9% and 18.3%, respectively, and in those who were exposed to vibration only, it was 23.9% in males and 26.4% in females. Insomnia in those who were exposed to both noise and vibration simultaneously was 20.5% and 41.2% in men and women, respectively. The odds ratio (OR) of insomnia due to noise exposure was 1.10 and 1.07 in men and women, respectively. OR of vibration exposure was 1.84 in men and 1.58 in women. For noise plus vibration exposure OR was 1.83 in men and 3.14 in female workers, where the synergistic effect of noise and vibration exposure could be seen. The association between the varying degree of simultaneous noise plus vibration exposure with insomnia showed a dose–response relationship. The interaction measures showed a synergistic effect of simultaneous exposure in women but not in men. Conclusion: Our study revealed an association between occupational noise and vibration exposure and insomnia, both individually and simultaneously. Additional studies and research are required to further comprehend this relationship.