The association between low blood lead levels and the prevalence of prehypertension among nonhypertensive adults in Korea.

OBJECTIVES: Low-level lead exposure has been associated with increases in blood pressure (BP) and impairment of the cardiovascular system. Prehypertension is not categorized as a disease currently; however, individuals with untreated prehypertension are known to be at increased risk of progression to hypertension and mortality caused by cardiovascular disease. We investigated the association between blood lead levels below the threshold for the harmful effects of lead and the prevalence of prehypertension in Korean adults. METHODS: A total of 8,493 participants (3,945 men and 4,548 women) were included in the current analysis, using data from the fourth, fifth, and sixth Korean National Health and Nutrition Examination Survey (KNHANES) in 2007-2013. Blood analysis, self-report questionnaires, and physical examinations were used to assess blood lead levels, BP, and medical history. Odds ratios (OR) and 95% confidence intervals (95% CI) for prehypertension were calculated using multiple logistic regression models. RESULTS: Compared to the first quartile (Q1) blood lead level (0.206-1.539 µg/dl), the ORs (95% CI) were 1.24 (1.04-1.48) in Q2, (1.540-2.056 µg/dl), 1.27 (1.06-1.52) in Q3, (2.057-2.716 µg/dl), and 1.30 (1.07-1.60) in Q4 (2.717-24.532 µg/dl) for the prevalence of prehypertension after adjusting for age, sex, morbidity status, socioeconomic status, and health behavioral variables. CONCLUSIONS: Our large, cross-sectional, nationwide study revealed that blood lead levels below the threshold for the harmful effects of lead were significantly associated with prehypertension. Am. J. Hum. Biol. 28:729-735, 2016. © 2016 Wiley Periodicals, Inc.

Metabolic outcomes of workers according to the International Standard Classification of Occupations in Korea.

BACKGROUND: Occupation influences the risk for developing chronic metabolic diseases. METHODS: We compared the prevalence of MetS by International Standard Classification of Occupations using the nationally representative data in Korea (KNHANES). We enrolled 16,763 workers (9,175 males; 7,588 females) who had measurements for the National Cholesterol Education Program criteria III and other variables. OR and 95%CIs for MetS and its components were estimated according to occupation using the multiple logistic regression models. RESULTS: The occupational groups with the highest age-standardized prevalence of MetS were lower skilled white-collar men (31.1 ± 2.4%) and green-collar women (24.2 ± 2.9%). Compared with the unskilled male blue-collar group, which had the lowest prevalence of MetS, the OR (95%CIs) of MetS in men were 1.77 (1.45-2.15) in higher skilled white-collar, 1.82 (1.47-2.26) in lower-skilled white-collar, 1.63 (1.32-2.01) in pink-collar and 1.37 (1.13-1.66) in skilled blue-collar workers in final logistic regression model. CONCLUSIONS: MetS and its components vary by occupational category and gender in ways that may guide health interventions. Am. J. Ind. Med. 59:685-694, 2016. © 2016 Wiley Periodicals, Inc.

Concealing Emotions at Work Is Associated with Allergic Rhinitis in Korea.

Concealing emotions at work can cause considerable psychological stress. While there is extensive research on the adverse health effects of concealing emotions and the association between allergic diseases and stress, research has not yet investigated whether concealing emotions at work is associated with allergic rhinitis. Allergic rhinitis is a common disease in many industrialized countries, and its prevalence is increasing. Thus, our aim was to determine the strength of this association using data from three years (2007-2009) of the 4th Korean National Health and Nutrition Examination Survey. Participants (aged 20-64) were 8,345 individuals who were economically active and who had completed the questionnaire items on concealing emotions at work. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated for allergic rhinitis using logistic regression models. Among all participants, 3,140 subjects (37.6%) reported concealing their emotions at work: 1,661 men and 1,479 women. The OR (95% CIs) for allergic rhinitis among those who concealed emotions at work versus those who did not was 1.318 (1.148-1.512). Stratified by sex, the OR (95% CIs) was 1.307 (1.078-1.585) among men and 1.346 (1.105-1.639) among women. Thus, individuals who concealed their emotions at work were significantly more likely to have a diagnosis of AR in comparison to those who did not. Because concealing emotions at work has adverse health effects, labor policies that aim to reduce this practice are needed.

Hospital Qualities Related to Return to Work from Occupational Injury after Controlling for Injury Severity as Well as Occupational Characteristics.

We examined associations between hospital quality in the workers' compensation system and injured patients' return to work after controlling for injury severity, occupational factors, and demographic factors. Return to work data of injured workers were constructed from 2 datasets: 23,392 patients injured in 2009-2011 from the Korea Workers' Compensation & Welfare Service and return to work data from Korea Employment Information Services. After de-identifying the data, quality scores were matched for each hospital that cared for injured patients. Injury severity was measured by Abbreviated Injury Scales. Relative risk and 95% confidence interval were calculated using log binomial regression models. After adjusting for age, sex, injury severity, occupation, factory size, city, and hospital type, the relative risk (95% confidence interval) for the total score was 1.04 (1.02-1.06), 1.06 (1.04-1.09), and 1.07 (1.05-1.10) in the 2(nd), 3(rd), and 4(th) quartiles, respectively, compared to the 1(st) quartile. The RR (95% CI) in the 2(nd), 3(rd), and 4(th) quartiles was 1.05 (1.02-1.07), 1.05 (1.02-1.08), and 1.06 (1.04-1.09) for the process score; and 1.02 (1.01-1.04), 1.05 (1.03-1.07), and 1.06 (1.04-1.09) for the outcome score compared to the 1(st) quartile score, respectively. In conclusion, our study design with blinded merge methods shows that total, process, and outcome qualities are related to the return to work of injured workers after controlling for other factors.

The Perceived Socioeconomic Status Is an Important Factor of Health Recovery for Victims of Occupational Accidents in Korea.

We aimed to examine whether there is a correlation between the health recovery of industrial accident victims and their perceived socioeconomic status. Data were obtained from the first Panel Study of Worker's Compensation Insurance, which included 2,000 participants. We performed multivariate regression analysis and determined the odds ratios for participants with a subjectively lower socioeconomic status and for those with a subjectively lower middle socioeconomic status using 95% confidence intervals. An additional multivariate regression analysis yielded the odds ratios for participants with a subjectively lower socioeconomic status and those with a subjectively upper middle socioeconomic class using 95% confidence intervals. Of all participants, 299 reported a full recovery, whereas 1,701 did not. We examined the odds ratio (95% confidence intervals) for participants' health recovery according to their subjective socioeconomic status while controlling for sex, age, education, tobacco use, alcohol use, subjective state of health prior to the accident, chronic disease, employment duration, recovery period, accident type, disability status, disability rating, and economic participation. The odds of recovery in participants with a subjectively lower middle socioeconomic status were 1.707 times greater (1.264-2.305) than that of those with a subjectively lower socioeconomic status. Similarly, the odds of recovery in participants with a subjectively upper middle socioeconomic status were 3.124 times greater (1.795-5.438) than that of those with a subjectively lower socioeconomic status. Our findings indicate that participants' perceived socioeconomic disparities extend to disparities in their health status. The reinforcement of welfare measures is greatly needed to temper these disparities.

Relationship between symptoms of dry eye syndrome and occupational characteristics: the Korean National Health and Nutrition Examination Survey 2010-2012.

BACKGROUND: Dry Eye Syndrome (DES) is a broad spectrum of uncomfortable ocular conditions that are caused by reduced production of tears or an increased tear evaporation rate. This study evaluated the relationship between symptoms of DES and occupational characteristics to identify the occupation-dependent differences in the prevalence of symptoms of DES using the Korean National Health and Nutrition Examination Survey V (2010-2012) data. METHODS: A total of 6023 participants were included (3203 men and 2820 women). Questionnaires and physical examinations were used to record clinical characteristics, occupational characteristics and medical history. Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for symptoms of DES were calculated according to the occupational characteristics. RESULTS: Among the participants, 963 persons (16.0 %) had symptoms of DES. An increased risk (relative to the green-collar group) was observed for the ordinary white-collar (OR, 1.73; 95 % CI, 1.73-1.41), executive white-collar (OR, 1.40; 95 % CI, 1.02-1.92) and skilled blue-collar (OR, 1.44; 95 % CI, 1.04-2.00) groups. Furthermore, paid workers had a significantly higher risk of dry eye symptoms (OR, 1.21; 95 % CI, 1.02-1.45), compared to self-employed workers. CONCLUSION: Our study is the first research to reveal that white-collar workers have a higher risk of symptoms of DES than blue-collar workers, that skilled blue-collar workers have a higher risk than unskilled blue-collar workers, and that paid workers have a higher risk than self-employed workers.

Workplace Violence Experienced by Substitute (Daeri) Drivers and Its Relationship to Depression in Korea.

Workplace violence is related to various health effects including mental illness such as anxiety or depression. In this study, the relationship between the experience of workplace violence and depression in substitute drivers in Korea, namely, daeri drivers, was investigated. To assess workplace violence, questions regarding types and frequency of the experience of violence over the past year were asked to the daeri drivers. In order to assess the risk of depression, the Center for Epidemiological Studies Depression Scale was used. Odds ratios with 95% confidence intervals of depression were estimated using multiple logistic regression analysis. All of the daeri drivers had experienced instance of verbal violence while driving and 66 of the drivers (34.1%) had been in such a situation more than once in the past quarter of a year. Sixty-eight daeri drivers (42.2%) had experienced certain type of physical violence over the past year. Compared to daeri drivers who had experienced workplace verbal violence less than 4 times and who had not experienced workplace physical violence over the past year, higher odds ratio was observed in daeri drivers who had experienced workplace verbal violence or physical violence, more than 4 times and more than one time respectively, after adjustment. Experience of verbal or physical type of workplace violence over the past year increased the risk of depression in the daeri drivers. Because violence against drivers can compromise the safety of the driver, the customer, and all the passengers, it is imperative that the safety and health of daeri drivers be highlighted.

Association between interleukin-1, interleukin-6, and tumor necrosis factor-alpha polymorphisms and juvenile idiopathic arthritis: a meta-analysis.

INTRODUCTION: In juvenile idiopathic arthritis (JIA), interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are associated with development and progression of JIA. We investigated whether IL-1, IL-6, and TNF-α polymorphisms were associated with susceptibility to JIA. EVIDENCE ACQUISITION: A meta-analysis was conducted on the associations between IL-1α-899 C/T, IL-1ß-511 C/T, IL-6-174 G/C, and TNF-α-308 G/A and -238 G/A polymorphisms, and JIA (PubMed and Embase). EVIDENCE SYNTHESIS: A total of 27 studies involving 4678 JIA patients and 7634 controls were considered in the meta-analysis. There was no association between the IL-1α-899 C/T, IL-1ß-511 C/T, IL-6-174 G/C, and TNF-α-308 G/A and -238 G/A polymorphisms, and JIA in allele contrast or any other genetic models. In subgroup analysis based on subtype, except for the dominant model of TNF-α-238 G/A, systemic JIA was not significantly associated with IL-6 and TNF-α polymorphisms. In Caucasians, the dominant and additive models of IL-1ß-511 C/T were significantly associated with JIA (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.09-2.00, P=0.01; OR 1.46, 95% CI 1.05-2.03, P=0.02, respectively). CONCLUSIONS: This meta-analysis showed no association between IL-1, IL-6, and TNF-α polymorphisms, and JIA, but the TT genotype of IL-1ß -511 C/T was associated with higher prevalence of JIA in Caucasians.

Prevalence of chronic obstructive pulmonary disease in patients with rheumatoid arthritis: A cross-sectional study.

OBJECTIVE: Rheumatoid arthritis (RA) and chronic obstructive pulmonary disease (COPD) are both chronic inflammatory diseases; the prevalence of COPD in RA patients is known to be high. However, the prevalence of both RA and COPD differs according to sex; the relationship between RA and COPD may also vary according to sex. Therefore, we investigated the prevalence of COPD and its association in patients with RA in Korea by sex. METHODS: We conducted a nationwide cross-sectional study using data from the Korea National Health and Nutrition Examination Survey. A total of 12 417 men and 15 878 women were included. In this study, RA was defined as physician diagnosed or currently under RA treatment. COPD was defined based on spirometry results, chronic symptoms, and smoking history. Multivariable logistic regression models were employed and we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for COPD prevalence in patients with RA. RESULTS: The prevalence of COPD was 15.5% in men with RA, 3.5% in women with RA, 7.8% in men without RA, and 2.2% in women without RA. After adjustment for potential confounding variables, including smoking status, RA was significantly associated with COPD in men (OR 2.16, 95% CI 1.06-4.40), but not in women (OR 1.58, 95% CI 0.81-3.10). CONCLUSIONS: In Korea, the prevalence of COPD was high in patients with RA of both sexes; RA and COPD was significantly likely to be associated in men, but not in women.

Relationship between coffee consumption and serum uric acid level in the general Korean population: A nationwide cross-sectional study.

OBJECTIVE: Coffee is one of the world's most consumed beverages, and its consumption is increasing. Serum uric acid levels are affected by dietary factors, and increased levels can cause a variety of diseases, including gout. This study aimed to investigate the relationship between coffee consumption and serum uric acid levels in the general Korean population. METHODS: A nationwide cross-sectional study was conducted using data from the Korean National Health and Nutrition Examination Survey in 2016. A total of 3005 participants who checked serum uric acid levels and a completed coffee consumption survey were included (1146 men and 1859 women). The amount of coffee consumption was examined via self-reporting and categorized as none, <1 cup, 1-2 cups, 2-5 cups, and ≥5 cups of coffee consumed daily. RESULTS: The mean serum uric acid level of the men was 5.91 ± 1.24 mg/dL and that of women was 4.29 ± 0.97 mg/dL. In the multiple linear regression analysis, there were no significant differences in the serum uric acid levels between the non-coffee-drinking group and the coffee-drinking group (<1 cup, 1-2 cups, 2-5 cups, and ≥5 cups of coffee) in both men and women (P = .569, .258, .466, and .751, respectively, in men; .185, .520, .116, and .302, respectively, in women). CONCLUSIONS: There was no significant relationship between coffee consumption and serum uric acid levels in the general Korean population.

The negative impact of long working hours on mental health in young Korean workers.

Long working hours are known to have a negative effect on health. However, there is no clear evidence for a direct link between mental health and long working hours in the young adult populations. Therefore, we aimed to determine whether long working hours are associated with mental health in young adult workers. Data were collected from a 2012 follow-up survey of the Youth Panel 2007. A total of 3,332 young adult employees (aged 20 to 35) were enrolled in the study. We analyzed stress, depression, and suicidal thoughts by multivariate logistic regression analysis based on working hours (41 to 50, 51 to 60 and over 60 hours, compared to 31 to 40 hours per week), which was adjusted for sex, age, marriage status, region, and educational level. From the 3,332 young adult employees, about 60% of the workers worked more than 40 hours and 17% of the workers worked more than 50 hours per week. In a Chi-square test, stress level, depression, and suicidal thoughts increased with increasing working hours (p-value <0.001, 0.007, and 0.018, respectively). The multivariate logistic regression model showed that, compared to the 31 to 40 hours per week group, the adjusted odds ratios of the 41 to 50, 51 to 60, and over 60 hours per week groups for stress were 1.46(1.23-1.74), 2.25(1.79-2.83) and 2.55(1.72-3.77), respectively. A similar trend was shown in depression [odds ratios: 2.08(1.23-3.53), 2.79(1.44-5.39) and 4.09(1.59-10.55), respectively] and suicidal ideation [odds ratios: 1.98(0.95-4.10), 3.48(1.48-8.19) and 5.30(1.61-17.42), respectively]. We concluded that long working hours were associated with stress, depression, and suicidal ideation in young employees, aged 20 to 35.

Relationship of rheumatoid arthritis and coronary artery disease in the Korean population: a nationwide cross-sectional study.

BACKGROUND: Rheumatoid arthritis (RA) is known to be associated with coronary artery diseases (CAD). Previous studies of the association between RA and CAD were reported mainly in non-Asian groups. We aimed to examine the prevalence of RA and the relationship between RA and CAD in South Korea. METHODS: We conducted a nationwide cross-sectional study by using the Korea National Health and Nutrition Examination Survey, which collected data for four years between 2008 and 2012. A total of 25,828 eligible participants were included. To balance the distribution of baseline characteristics, we used propensity score-matching. A multivariable logistic regression model was employed and we calculated the odds ratios (ORs) and 95% confidence intervals (CI) for the odds of the participants with RA on CAD prevalence. RESULTS: The prevalence of RA in Korea from 2008 to 2012 was 0.6% and RA was predominant among elderly women. The prevalence of CAD in patients with RA was significantly higher than in general population. After propensity score-matching to balance the confounding factors, RA was significantly associated with CAD (OR 2.97, 95% CI 1.15-7.68, P = 0.02). CONCLUSIONS: The prevalence of RA in South Korea was comparable to the worldwide data, and the presence of CAD in RA patients was more than two-fold.

Association between rs1800795 polymorphisms in the interleukin-6 gene and vasculitis: A meta-analysis.

Interleukin (IL)-6 is associated with the development and progression of vasculitis, and inhibitors of this cytokine are used to treat this disease. Polymorphisms of the promoter region of IL-6 are associated with the production and expression of IL-6. The aim of this study was to perform a meta-analysis of eligible studies to derive a precise estimate of the association between IL6 polymorphisms and susceptibility to vasculitis. A meta-analysis was conducted to identify the associations between IL6 rs1800795 (-174 G/C) polymorphisms and vasculitis. A total of 13 studies involving 1,294 vasculitis patients and 1,594 controls were considered in the meta-analysis. There were significant associations between IL6 rs1800795 polymorphisms and vasculitis in allele contrast, dominant genetic model, and heterozygote vs. dominant homozygote comparison (OR 0.80, 95% CI 0.67-0.94, P =0.009 and OR 0.76, 95% CI 0.63-0.92, P =0.005, respectively). In subgroup analysis based on subtype, there were significant associations between IL6 polymorphisms and susceptibility in large and medium vessel vasculitis, but not in small and variable vessel vasculitis. The GC genotype of IL6 rs1800795 was suggested by the analyses to be related to low prevalence of vasculitis, especially for large and medium vessels.

Clinical Findings of Ankylosing Spondylitis With and Without Human Leukocyte Antigen (HLA)-B27 and HLA-B51.

INTRODUCTION: Ankylosing spondylitis (AS) and Behçet's disease are known to be associated with the human leukocyte antigen (HLA)-B27 and HLA-B51 genes, respectively. However, many of their clinical findings-including articular and extra-articular symptoms-are similar, making diagnosis a challenge in the early stage of the disease. The aim of this study was to investigate the differences in clinical findings of AS patients with and without the HLA-B27 gene. MATERIALS AND METHODS: We performed a retrospective chart review of 151 AS patients. The following clinical findings were evaluated: oral ulcer, genital ulcer, skin manifestation, uveitis, peripheral arthritis; and gastrointestinal, cardiac and pulmonary involvement. Patients were divided into 4 groups based on absence or presence of the HLA-B27 and HLA-B51 genes. The number of patients with each clinical finding was subsequently examined in each group. RESULTS: The incidence of uveitis was significantly higher in the HLA-B27-positive group (P = 0.004); however, other clinical findings did not differ significantly according to the absence or presence of the HLA-B27 gene. There were no significant differences in the clinical findings of patients with positive and negative HLA-B51. CONCLUSION: HLA-B27 was associated with the development of uveitis but not with other clinical findings or disease activity in AS patients. HLA-B51 was not associated with the clinical findings or disease activity of AS.

Long Working Hours and Poor Self-Rated Health in the Young Working Population in Korea.

: This cross-sectional study investigated the association between long working hours and prevalence of poor self-rated health (SRH) in Korean young workers using data from the 6th Korea Youth Panel Survey 2007. A total of 3317 young wage workers were included. Weekly working hours were divided into four groups (36 to 40 hours, 41 to 52 hours, 53 to 60 hours, and more than 60 hours per week). Multiple logistic regression was performed to investigate the association between long working hours and SRH, adjusting for demographic and work-related factors. Long working hours were associated with increased risk of poor SRH, in both the men and women. Legal restriction on working hours should be suitably applied to help improve the health status of Korean young workers.

Association between occupational clusters and allergic rhinitis in the Korean population: analysis of the Korean National Health and Nutrition Examination Survey data.

OBJECTIVES: This study aimed to investigate the association between occupational clusters and allergic rhinitis (AR). METHODS: The study was based on data from the Korean National Health and Nutrition Examination Survey (KNHANES: 2007-2015). This study included 46,965 individuals: 20,491 men and 26,474 women. AR was defined as having been diagnosed by a physician. Occupations were classified according to occupational characteristics and skill levels into white (chief executives, senior officials, legislators, managers, professionals, and technicians), pink (clerks, clerical support workers, services and sales workers), blue (craft and related trades workers, drivers, plant and machine operators, assemblers, elementary occupation workers), and green (skilled agricultural, forestry, and fishery workers) categories. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) of AR according to the occupational clusters by using the chi-squared test and logistic regression. RESULTS: In the study population, 10.7% of the men and 13.5% of the women had AR. The prevalence of AR was highest among white-collar workers, followed by pink, blue, and green-collar workers. Compared to green-collar workers, among men the adjusted ORs of the blue, pink, and white-collar workers were 2.00 (95% CI 1.58-2.53), 2.46 (95% CI 1.91-3.15), and 2.78 (95% CI 2.20-3.51), respectively; and among women were 2.45 (95% CI 1.99-3.02), 2.64 (95% CI 2.15-3.25), and 3.63 (95% CI 2.96-4.47), respectively. CONCLUSIONS: This study suggests that AR prevalence is significantly associated with occupational clusters.

Association between osteoarthritis and mental health in a Korean population: a nationwide study.

AIM: Osteoarthritis (OA) is a chronic disease and has become a major health problem in recent years. OA causes chronic pain and disability and can induce mental disorders such as stress perception, depression and suicidal ideation. We investigated the incidence of perceived stress, depressed mood and suicidal ideation in OA patients, using the 2010-2012 Korea National Health and Nutrition Examination Survey (KNHANES). METHOD: A total of 8271 participants were included (3580 male and 4691 female). OA patients were defined as participants with knee/hip joint pain and radiographic changes of the knee/hip joints. Mental disorders included stress perception, depression and suicidal ideation. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for mental disorders were calculated according to the OA. RESULTS: In the multiple logistic regression model, compared to the non-OA group, the ORs of high stress perception, depression and suicidal ideation were 1.59 (95% CI 1.10-2.31), 1.52 (95% CI 1.01-2.29) and 1.90 (95% CI 1.33-2.72), respectively, in male, and 1.41 (95% CI 1.19-1.68), 1.27 (95% CI 1.04-1.54) and 1.49 (95% CI 1.25-1.78), respectively, in female. CONCLUSION: OA is associated with impaired mental health. OA patients had high stress perception, depression and suicidal ideation. More numbers of male with OA had much more mental disorders than female with OA.

The association between osteoarthritis and sleep duration in Koreans: a nationwide cross-sectional observational study.

Osteoarthritis (OA) causes chronic pain, physical disability, and mental health deterioration and reduces the quality of life of patients. Sleep is an important factor in the recovery, and adequate sleep is important for quality of life. Several features of patients with OA can affect sleep time, and sleep also affects OA. We investigated the relationship between OA and sleep duration. Data for 2010-2012 were collected from the Korea National Health and Nutrition Examination Survey. We included 11,540 participants (4915 men and 6625 women). Patients with OA were defined as participants with knee/hip joint pain and radiographic changes of the knee/hip joints. Sleep time was divided into 4 sections as follows: (1) 0-3 h, (2) 4-5 h, (3) 6-7 h, and (4) ≥ 8 h. Sleep time of 6 and 7 h was the most frequent and set as the reference time. In the multiple logistic regression model, the patients who slept for 0-3 and 4-5 h had odds ratios (ORs) of 2.28 (95% confidence interval [CI] 1.14-4.55) and 1.38 (95% CI 1.01-1.89) for men and 1.63 (95% CI 1.19-2.24) and 1.26 (95% CI 1.08-1.47) for women, respectively, for having OA. The prevalence of OA was lowest in the participants who had 6-7 h of sleep and progressively increased with shorter sleep time. Thus, sleep duration was significantly associated with OA.

The association between subjective socioeconomic status and health inequity in victims of occupational accidents in Korea.

OBJECTIVES: We aimed to investigate the health inequity of victims of occupational accidents through the association between socioeconomic status and unmet healthcare need. METHODS: Data from the first and second Panel Study of Workers' Compensation Insurance were used, which included 1,803 participants. The odds ratio and 95% confidence intervals for the unmet healthcare needs of participants with a lower socioeconomic status and other socioeconomic statuses were investigated using multivariate regression analysis. RESULTS: Among all participants, 103 had unmet healthcare needs, whereas 1,700 did not. After adjusting for sex, age, smoking, alcohol, chronic disease, recuperation duration, accident type, disability, and economic participation, the odds ratio of unmet healthcare needs in participants with a lower socioeconomic status was 2.04 (95% confidence interval 1.32-3.15) compared to participants with other socioeconomic statuses. CONCLUSIONS: The victims of occupational accidents who have a lower socioeconomic status are more likely to have unmet healthcare needs in comparison to those with other socioeconomic statuses.

The relationship between occupational noise and vibration exposure and headache/eyestrain, based on the fourth Korean Working Condition Survey (KWCS).

INTRODUCTION: The individual and combined effect of occupational noise and vibration exposures, on workers' health has not been thoroughly investigated. In order to find better ways to prevent and manage workers' headache, this study aimed to investigate the effects of occupational noise and vibration exposure on headache/eyestrain. METHODS: We used data from the fourth Korean Working Condition Survey (2014). After applying inclusion and exclusion criteria, 25,751 workers were included. Occupational noise and vibration exposure and the prevalence of headache/eyestrain were investigated by self-reported survey. Chi-square tests were used to compare differences in baseline characteristics between the group with headache/eyestrain and the group without. Odds ratios and 95% confidence intervals were estimated using a logistic regression model adjusted for several covariates. Area under the receiver operating characteristics curve (AUROC) analysis was used to evaluate the effect of occupational noise and/or vibration exposure. RESULTS: Among the 25,751 study subjects, 4,903 had experienced headache/eyestrain in the preceding year. There were significant differences in age, education level, household income, occupational classification, shift work, occupational vibration exposure, and occupational noise exposure between the two groups (all p<0.05). The odds ratios between each exposure and headache/eyestrain increased proportionally with the level of exposure, increasing from 1.08 to 1.26 with increasing vibration exposure, and from 1.25 to 1.41 with increasing noise exposure. According to the AUROC analysis, the predictive power of each exposure was significant, and increased when the two exposures were considered in combination. DISCUSSION: The findings of this study show that both occupational noise and vibration exposures are associated with headache/eyestrain; noise exposure more strongly so. However, when the two exposures are considered in combination, the explanatory power for headache/eyestrain is increased. Therefore, efforts aimed at reducing and managing occupational noise and vibration exposure are crucial to maintaining workers' health.