Co-worker perceptions of return-to-work opportunities for Japanese cancer survivors.

PURPOSE: This study examined workplace factors and perceptions of Return-to-Work (RTW) opportunities for colleagues with cancer-related symptoms and/or treatment side effects in Japan. METHODS: We conducted an online, cross-sectional survey of 3710 employed Japanese individuals of working age. Colleagues' perceptions of RTW opportunities for cancer survivors were examined (using a Japanese questionnaire), along with workplace factors such as job demand, job control and workplace social support (using the Brief Job Stress Questionnaire). Associations between workplace factors and RTW opportunities were evaluated using multiple logistic regression analysis, with participants stratified in tertiles (low, middle and high) according to their levels of workplace social support and job control. RESULTS: Colleagues' perceptions of inadequate RTW opportunities were associated with low workplace social support (middle tertile: Odds Ratio [OR] 1.22, 95% Confidence Interval [CI]: 1.08-1.36; low tertile: OR 1.43, 95%CI: 1.30-1.57; p for trend <0.01); low levels of job control (middle tertile: OR 1.27, 95%CI: 1.06-1.50; low tertile: OR 1.91, 95%CI: 1.64-2.21; p for trend <0.01); and no prior experience working with a cancer survivor (OR 2.08, 95%CI: 1.83-2.31). CONCLUSIONS: This study suggests that workplace factors and prior experience of working with a cancer survivor may affect a colleagues' perception of RTW opportunities in Japanese workplaces. Consideration of workplace social factors (workplace support and job control), as well as increased openness and awareness of the particular needs of cancer survivors, is therefore essential to facilitate successful RTW in Japan, as elsewhere.Copyright © 2016 John Wiley & Sons, Ltd.

Decrease in Work Ability Index and sickness absence during the following year: a two-year follow-up study.

PURPOSE: Using a 2-year follow-up design, we examined whether changes in work ability during 1 year predicted sickness absence in the following year. METHODS: Workers (N = 1408) from the Japanese information technology sector each completed the Work Ability Index (WAI), the Brief Job Stress Questionnaire (BJSQ), and the General Health Questionnaire (GHQ) in 2011 and 2012. Absence data during 2013 was obtained from employees' computerized attendance records. We used psychological distress as evaluated by the GHQ; job stress and job support calculated using the BJSQ; and job title, sex, and age as potential confounding variables. RESULTS: Thirty-five employees had at least one sickness absence lasting more than seven consecutive days in 2013. Forty-nine percent of sickness absences were due to mental illness, and the others were due to orthopedic disease (20%), cancer (9%), and other illnesses (23%). Decrease in WAI scores from 2011 to 2012 predicted sickness absence in 2013 (Odds ratio (OR) 1.19, 95% confidence interval (CI) 1.12-1.27). This association remained unaltered after adjusting for sex, age, job title, WAI score from the year before, job stress, job support, and GHQ score (OR 1.15, 95% CI 1.06-1.25). We analyzed this association separately by reason for absence: mental or other illness. WAI score decreases predicted sickness absence for both reasons (OR for mental illness 1.24, 95% CI 1.14-1.36; OR for other illnesses 1.14, 95% CI 1.04-1.24). CONCLUSIONS: Decrease in work ability during the year predicts sickness absence in the following year while predictive power was weak.

Psychosocial factors and colleagues' perceptions of return-to-work opportunities for workers with a psychiatric disorder: a Japanese population-based study.

BACKGROUND: This study examined associations between psychosocial factors and the perception that adequate employment opportunities might not be provided for people with limited work capacity due to psychiatric disorders. METHODS: We conducted an online, cross-sectional survey of 3,710 employed individuals aged 20 to 69 years in Japan. Our survey included the Brief Job Stress Questionnaire and investigated participants' perception of opportunities in their workplace for individuals with a psychiatric disorder returning to work (colleagues' negative perception) and psychosocial factors (job demand, job control, and workplace social support). Multiple logistic regression analysis was used to evaluate potential associations between psychosocial factors and colleagues' negative perception. RESULTS: Colleagues' negative perception was associated with low workplace social support (middle tertile: Odds Ratio [OR]: 1.26, 95% Confidence Interval [CI]: 1.12-1.40; low tertile: OR 1.45, 95% CI: 1.32-1.58; p for trend <0.01); low levels of job control (middle tertile: OR 1.22, 95% CI: 1.06-1.38; low tertile: OR 1.64, 95% CI: 1.46-1.81; p for trend <0.01); and no previous experience working with a person with a psychiatric disorder (OR 1.74, 95% CI: 1.60-1.88). CONCLUSIONS: Psychosocial factors may affect colleagues' perceptions of individuals with a psychiatric disorder returning to work in Japan. Greater consideration of psychosocial factors in the workplace may be necessary to facilitate people with a psychiatric disorder successfully returning to work in Japan, as elsewhere.

Work improvement factors for the amelioration of work ability, with a focus on individual capacity to deal with stress in an IT company.

The aim of this study was to explore factors that ameliorate work ability by focusing on workers' capacity to deal with stress.The subjects were 1,330 workers from the Japanese information technology (IT) sector. Each subject completed questionnaires in 2011 and 2012 that consisted of the work ability index (WAI), the three-item sense of coherence (SOC), and the Mental Health Improvement and Reinforcement Research of Recognition (MIRROR). The results of the WAI were also obtained in 2013. The median SOC score in 2011 was used to divide the subjects into two groups, the Low SOC group and the High SOC group, then we verified the factors that contributed to improved work ability in both of these groups over a two-year period. Results indicate that an improvement in work ability in the Low SOC group could be predicted by giving workers opportunities for education or training, by making efforts to reduce the stress of commuting, by clarifying their assignments, and by establishing support systems when troubles occur. For the High SOC group, such improvements could be predicted by giving workers job control, by giving education or training for the promotion of their abilities, and by establishing a system for assuming responsibility. In conclusion, improvements in the work environment can increase the work ability of Japanese IT workers in conformity with their capacity to deal with stress.

[The relationships between public willingness to engage in cooperative childrearing and their attitudes toward cooperative childrearing, the local environment, and social capital].

OBJECTIVES: This study examines the relationship between people's willingness to cooperate with others in childrearing, and their attitudes toward such cooperation. The study also examines their thoughts about their local living environment, and their awareness of social capital in this regard. METHODS: In Study I, a questionnaire was constructed based on items derived from existing literature that examined people's willingness to cooperate with others in childrearing and their attitudes towards years, and living in A Town, were asked to fill out the questionnaire. In Study II, another questionnaire was constructed comprising 32 items derived from the questionnaire used in Study I that examined willingness to cooperate and attitudes toward cooperative childrearing. Furthermore, we added 15 items on the local living environment and 10 items on the elements constituting social capital. Three hundred and fifty-three mothers with pre-school children, 325 mothers with primary school children, and 383 women between 45 and 60 years of age, all living in the C Junior High School district in B City (a total of 1,061 respondents) completed the questionnaire. RESULTS: We conducted a factor analysis, and the following eight factors (derived from 32 items) were extracted, which related to willingness to cooperate in childrearing and attitudes toward cooperative childrearing: "It is necessary to cooperate in childrearing"; "I take care of others' children"; "I participate in festivals or local events"; "I play with children"; "Public assistance for children should be increased"; "I greet children"; "I observe people passing in front of my house"; and "I help with In Study II, we also identified a factor that influenced willingness to cooperate in childrearing and attitudes toward cooperative childrearing: mothers' and local residents' awareness of the elements constituting social capital. Particularly noteworthy in this regard were the effects of conversation, consultation, and the lending and borrowing of household items between neighbors, friends, acquaintances, and relatives. CONCLUSION: Mothers' and local residents' awareness of the elements constituting social capital was identified as a factor that influences willingness to cooperate in childrearing and attitudes toward cooperative childrearing. In particular, connections and social interaction were shown to have primary influences.

[Evaluating the relationship between oral health status in male workers and question item regarding subjective chewing symptoms].

OBJECTIVES: In recent years, the relationship between oral health status and various diseases has been increasingly reported worldwide, leading to a growing understanding of the importance of oral health. This study aimed to investigate the relationship between oral health status, determined after a dental health check-up, and chewing condition, determined via a questionnaire for specific health check-ups with the newly added chewing condition item-When you chew your food, which most accurately describes your chewing-. METHODS: From 20,834 Japanese workers who underwent dental health check-ups and specific health check-ups from April 2018 to March 2019, 4,011 male workers (51.2 ± 6.1 years, range 40-64 years) were extracted for this study. Participants were divided into two groups, the good chewing condition group (GCG) and poor chewing condition group (PCG), according to their responses to a questionnaire regarding chewing conditions. We collected and compared data on subjects' age, smoking status, number of teeth present, number of filled teeth, number of decayed teeth, number of missing teeth with prosthetic treatment, periodontal pockets, gingival bleeding, oral hygiene status, and Eichner's classification. Additionally, to clarify the risk associated with chewing condition, we performed stepwise multiple logistic regression analysis with good chewing condition/poor chewing condition as the dependent variable, and age, smoking status, number of teeth present, number of filled teeth, number of missing teeth with prosthetic treatment, periodontal pockets, oral hygiene status, and Eichner's classification as the independent variables. RESULTS: The result of stepwise multiple logistic regression analyses, the odds ratio (OR) and 95% confidence interval (95% CI) of the factors that remained in the final model were as follows; the number of decayed teeth (OR = 1.18 [95% CI: 1.12-1.24]); periodontal pockets of 3 mm or less vs. 6 mm or more (OR = 1.63 [95% CI: 1.12-2.37]); Eichner's classification A1 vs. A2 (OR = 1.40 [95% CI: 1.08-1.82]), A3 (OR = 1.66 [95% CI: 1.09-2.52]), B1 (OR = 3.38 [95% CI: 2.04-5.61]), B2 (OR = 5.26 [95% CI: 2.46-11.2]), B3 (OR = 4.28 [95% CI: 1.20-15.2]), B4 (OR = 7.59 [95% CI: 1.06-54.5]). CONCLUSIONS: The results of this study suggest a significant association between the newly added "chewing condition" item in the questionnaire for specific health check-ups and oral status; the number of decayed teeth, periodontal pockets, Eichner's classification.

[Association between subjective chewing conditions and dietary habits in Japanese workers].

OBJECTIVES: Previous studies on the elderly have reported that they avoid fiber-rich and hard foods in favor of softer foods as chewing ability declines. However, evidence of worker chewing conditions and dietary habits is scarce. This study aimed to clarify the association between chewing conditions and dietary habits in workers. METHODS: The subjects included 6,703 workers (45.6 ± 10.2 years, range 18-64 years) who underwent medical and dental check-ups from April 2018 to March 2019 with no missing data. We classified workers into two groups, those with good chewing conditions (GCC) and those with poor chewing conditions (PCC) according to their responses to the chewing condition item in our questionnaire. We performed logistic regression analysis using the questionnaire dietary habits item response as the objective variable and chewing conditions as the explanatory variable and adjusting for sex, age, number of present teeth, periodontal pocket depth, oral hygiene status, Body Mass Index, smoking habits, alcohol intake, exercise habits, history of present illness, and stages of transtheoretical model. Additionally, we performed subgroup analysis using a similar framework stratified by sex and age groups (under 40 or older). RESULTS: We found significant negative associations with PCC for the following dietary habits (p < .05): Awareness of balanced diet; Regular consumption of dark green and deep yellow vegetables; Eating slowly and chewing well; Frequent consumption of seaweed and small fish; Having three meals at almost at the same time every day; Having breakfast almost every day; Eating protein dishes with every meal; Frequently consuming dairy products; Finishing eating at least two hours before bedtime. Furthermore, we found significant positive associations with PCC for the following items (p < .05): Having on average two or more bottles/cans of juice or coffee a day; Frequently eating heavy meat dishes; Frequently eating deep-fried foods such as fried dishes and pork cutlets; Frequently having instant or processed foods; Eating two or more kinds of Western or Japanese confectioneries or snacks on average a day; Frequently eating salty food; Regularly having snacks or late-night meals. Additionally, similar trends were also observed following subgroup analysis, regardless of sex or age. CONCLUSIONS: This study suggests that workers with PCC may retain undesirable dietary habits, regardless of sex and age. Therefore, it is necessary to expand dental check-ups in the workplace and to promote dental health guidance that targets all workers.

[Relationship between performance rating and risk of low back pain in manufacturing line workers].

It is possible that the performance rating of line workers is affected by the risk factors for musculoskeletal disorders that are included in their work more so than by the actual takt time. To investigate whether performance rating relates to the risk factors for musculoskeletal disorders, we analyzed a dataset obtained from a self-administered questionnaire answered by assembly line workers (n=1579). As a result, performance rating had a significant association with unsuitable work environments, poor working postures and handling of heavy loads. The workers who reported the fastest rating had a higher exposure than others to the risk factors for occupational low back pain. The results of our study support the effectiveness of performance rating as an index of work burden.

The effects of static trunk flexion on oxygenation and electromyographic activity of erector spinae muscles.

In the workplace, localized muscle fatigue can be a limiting factor for prolonged static work. It is important to study the etiology of fatigue in the muscle to prevent discomfort and potential muscle injury. The purpose of this study was to investigate the effect of sustained trunk flexion and loading on the erector spinae muscles (ESM) fatigue using electromyography (EMG) and muscle oxygenation (Mox) changes. Twelve healthy male volunteers, aged between 19 and 28 years (mean age 23 +/- 2.6), participated in this study. The subjects held a load (5, 10 and 15 kg) and no load in their hands whilst sustaining trunk flexion at 60 degrees and also in an upright standing posture for 30 seconds. Five minutes rest was given between the conditions, and each condition was randomly repeated three times. Surface EMG and near-infrared spectroscopy were recorded. Root mean square and median frequency (MF) of EMG, and Mox were calculated. The results showed a greater decrease in Mox with an increase in loads over time (P = 0.015). Using unloaded trunk flexion as a control to ascertain load effect resulted in a significant difference in Mox in the unloaded condition and in the 15 kg condition (P = 0.027). EMG results showed a significant decrease in the MF over time in trunk flexion while holding a load (P < 0.001). These results show objectively that trunk flexion while holding loads causes ESM fatigue.

Does difficulty in chewing induce subjective musculoskeletal symptoms? A case-control study.

OBJECTIVES: Risk factors associated with the development of musculoskeletal disorders and symptoms remain an important issue worldwide. This study aimed to investigate the relationship between oral health problems such as difficulty chewing and the occurrence of stiff neck/shoulders (SN/S) and low back pain (LBP). DESIGN: Case-control study. SETTING AND PARTICIPANTS: This study was conducted from 1 April 2018 to 31 March 2020. The subjects were 77 341 workers among 646 281 workers from several employers in Japan. OUTCOME MEASURES: Participants were asked to evaluate their subjective SN/S and LBP symptoms using a self-administered questionnaire. METHODS: We defined the chewing condition using a questionnaire, and workers who responded with 'I can chew anything' were classified as the good condition group (GCG), and those who responded with 'Sometimes I have difficulty chewing due to problems with the teeth, gums, or bite' or 'I can hardly chew' were classified as the poor condition group (PCG). Setting the year 2018 as the baseline, we performed a logistic regression model using propensity score and inverse probability weighting (IPW) methods and chewing condition groups as explanatory variables and SN/S and LBP as objective variables. RESULTS: The IPW-adjusted logistic regression model showed that the OR of SN/S was approximately 1.25 (95% CI 1.17 to 1.33) times higher in the PCG than that in the GCG (p<0.001). Similarly, the OR of LBP was about 1.37 (95% CI 1.27 to 1.48) times higher in the PCG than that in the GCG in the IPW-adjusted logistic regression model (p<0.001). CONCLUSIONS: Our study suggests that the occurrence of SN/S and LBP symptoms in workers could be predicted depending on the presence of difficulty in chewing. Therefore, oral health and health guidance are gaining importance for the prevention of subjective musculoskeletal symptoms.

[Verification of the effects of three percent weight loss at 6 months and application possibility of assessment at 3 months after the specific health guidance for male workers].

OBJECTIVES: This study aimed to evaluate the effects of ≥ 3% body weight loss at 6 months in male workers and verify the application possibility of assessment at 3 months after specific health guidance. METHODS: We recruited 5,031 Japanese male workers (aged 40-64 years) who had undergone health checkups and completed specific health guidance from 2008 to 2017. Participants were divided into three groups according to the percentage of weight reduction (≥ 3%, 0%-3%, ≤ 0%) after 6 months of health guidance. We compared the body weight, waist circumference, and blood pressure at 3- and 6-months with baseline data within and between groups. Similarly, in the medical examination of the next fiscal year (n = 2,889), body weight, waist circumference, blood pressure, triglyceride levels, high-density lipoprotein-cholesterol (HDL-C) levels, plasma glucose levels, and the prevalence and improvement rates of metabolic syndrome (MetS) of specific health checkups were also compared. Furthermore, we calculated the weight reduction target after 3 months to arrive at a ≥ 3% weight reduction for 6 months. Based on the target, we investigated the prevalence and improvement rates of MetS in the next fiscal year. RESULTS: A total of 1,349 (26.8%) participants had a ≥ 3% weight reduction, 2,059 (40.9%) had a < 3% weight reduction, and 1,623 (32.3%) had no weight reduction. At the 6-month follow-up, waist circumference and blood pressure levels had increasingly improved with greater reductions in weight. The following year, body weight, waist circumference, blood pressure, triglyceride levels, HDL-C levels, and plasma glucose levels had improved in the ≥ 3% weight loss group, whereas plasma glucose levels had not improved in the 0-3% weight loss group. Additionally, only triglyceride levels and diastolic blood pressure had improved in the no weight reduction group. In the ≥ 3% weight loss group, the prevalence rate of MetS was the lowest (7.6%), and the improvement rate of MetS was the highest (70.7%). Furthermore, the weight reduction target after 3 months to arrive at a ≥ 3% body weight reduction at 6 months was 2.0% weight reduction. Those who reduced weight ≥ 2.0% had better prevalence and improvement rates of MetS than those who reduced weight < 2.0%. CONCLUSIONS: Our findings indicated that the objective of losing ≥ 3% of body weight at 6 months in male workers after completing specific health guidance was effective and that assessment after 3 months based on setting a 2.0% weight reduction target was applicable.

Development of a simple measurement scale to evaluate the severity of non-specific low back pain for industrial ergonomics.

This study developed an assessment scale that hierarchically classifies degrees of low back pain severity. This assessment scale consists of two subscales: 1) pain intensity; 2) pain interference. First, the assessment scale devised by the authors was used to administer a self-administered questionnaire to 773 male workers in the car manufacturing industry. Subsequently, the validity of the measurement items was examined and some of them were revised. Next, the corrected low back pain scale was used in a self-administered questionnaire, the subjects of which were 5053 ordinary workers. The hierarchical validity between the measurement items was checked based on the results of Mokken Scale analysis. Finally, a low back pain assessment scale consisting of seven items was perfected. Quantitative assessment is made possible by scoring the items and low back pain severity can be classified into four hierarchical levels: none; mild; moderate; severe. STATEMENT OF RELEVANCE: The use of this scale devised by the authors allows a more detailed assessment of the degree of risk factor effect and also should prove useful both in selecting remedial measures for occupational low back pain and evaluating their efficacy.

Lifestyle and subjective musculoskeletal symptoms in young male Japanese workers: A 16-year retrospective cohort study.

This longitudinal study was conducted from 2002 to 2018 and aimed to investigate predictive lifestyle factors for the occurrence of subjective musculoskeletal symptoms. The participants came from several employers in Japan. Setting 2002 as the baseline, we performed logistic regression analyses using lifestyle questionnaire items as explanatory variables and Stiff neck/shoulders (SN/S) and Lower back pain (LBP) as objective variables (n = 16,748). Workers who responded positively to good lifestyle items with an odds ratio < 1.0 and those who did not were classified in the Good (GL) and Poor lifestyle groups (PL), respectively. The survival period between the groups was compared using the log-rank test and Cox hazard regression analysis with propensity score matching (n = 3,593). Based on the Cox hazard regression analysis results, the risk of SN/S was about 2.54 (95% confidence interval [CI]: 1.80-3.59) times higher for PL than for GL (p < 0.001). Similarly, after propensity score matching, the risk was about 2.33 (95% CI: 1.07-5.10) times higher for PL than for GL (p < 0.05). Further, LBP risk was about 2.45 (95% CI: 1.67-3.58) times higher for PL than for GL (p < 0.001). Similarly, after propensity score matching, the risk was about 3.50 (95% CI: 1.60-7.68) times higher for PL than for GL (p < 0.01). This study highlighted that workers with four good lifestyle factors (life satisfaction, hours of sleep, exercise habits, and physical fitness) presented reduced risk of subjective musculoskeletal symptom occurrence. To prevent musculoskeletal symptoms, physicians and occupational health staff should advise on workers' individual lifestyle.

[A case study of tailor-made exercise for preventing decrease in physical function: Analyzing the effect of tailor-made exercise from a motion study, motor function test, and questionnaire].

OBJECTIVE: This study aimed to verify the effect of tailor-made exercise depending on the characteristics of a certain food manufacturing industry on the physical function and subjective symptoms of employees. METHODS: For the development of tailor-made exercise, work analysis was carried out at each factory to comprehend the physical burden due to work load. The motor function test and questionnaire survey for subjective symptoms were conducted before and after exercise during 3 months. The motor function tests included the 30-s chair-stand test and two-step test. RESULTS: There were significant improvements in the 30-s chair-stand test after tailor-made exercise intervention for men and women (men: 20.9±4.8 vs 27.9±5.1 counts/30 s, p < 0.01; women: 19.4±3.1 vs 23.7±2.7 counts/30 s, p < 0.01) but not in the two-step test. In addition, as a result of comparing the questionnaire survey for subjective symptoms before and after intervention, there was a significant difference (p < 0.05) in "stumbling and staggering within 1 month," "feeling of fatigue in the back," "feeling of fatigue in the right foot/ankle," and "feeling of fatigue in the left foot/ankle." CONCLUSIONS: It is thought that the leg muscle strength increased due to tailor-made exercise, and the stumbling and staggering improved. In addition, feeling of fatigue in the back and in the right and left foot/ankle was improved. It was suggested that tailor-made exercise intervention can significantly affect the physical function of employees.

Selective High-Frequency Mechanical Actuation Driven by the VO2 Electronic Instability.

Relaxation oscillators consist of periodic variations of a physical quantity triggered by a static excitation. They are a typical consequence of nonlinear dynamics and can be observed in a variety of systems. VO2 is a correlated oxide with a solid-state phase transition above room temperature, where both electrical resistance and lattice parameters undergo a drastic change in a narrow temperature range. This strong nonlinear response allows to realize spontaneous electrical oscillations in the megahertz range under a DC voltage bias. These electrical oscillations are employed to set into mechanical resonance a microstructure without the need of any active electronics, with small power consumption and with the possibility to selectively excite specific flexural modes by tuning the value of the DC electrical bias in a range of few hundreds of millivolts. This actuation method is robust and flexible and can be implemented in a variety of autonomous DC-powered devices.

Assessing the Impact of Nationwide Smoking Cessation Interventions among Employed, Middle-Aged Japanese Men, 2005-2010.

BACKGROUND: A variety of tobacco control interventions have become available in Japan over the past decade, however, the magnitude to which they have impacted on smoking rates may have varied by socioeconomic status such as job content, particularly for middle-aged men who were formerly long-term smokers. We conducted a longitudinal study to investigate the differences between smoking cessation strategies among a national sample of middle-aged Japanese employed men between 2005 and 2010. METHODS: Data was extracted from a previous longitudinal survey of middle-aged and elderly people that had been conducted by the Ministry of Health, Labour and Welfare. In 2005, 16,738 Japanese men aged 50-59 years were recruited and sent a questionnaire in each year of the study. We analyzed data for individuals who reported being current smokers at baseline. Cox's discrete time proportional hazard regression analysis was used to examine potential associations between smoking cessation and socioeconomic factors. RESULTS: Of the 6187 employed, male smokers who participated in 2005, 31% subsequently quit smoking during the 5-year follow-up period. Those working in manufacturing, transportation, or security were less likely to have quit smoking than those working in management. Having no marital partner, never having been married, or those experiencing psychological distress were significantly less likely to have quit smoking during this time. CONCLUSIONS: Although almost one-third of middle-aged, male smokers quit their habit between 2005 and 2010; the uptake of this national strategy appears to have been far from uniform across Japanese society. Socioeconomic factors such as occupation, marital status and psychological distress were negatively correlated with quitting, suggesting that these groups should be more aggressively targeted in further interventions.

Socioeconomic status and self-reported health among middle-aged Japanese men: results from a nationwide longitudinal study.

OBJECTIVE: To examine potential associations between socioeconomic factors and self-rated health among a national sample of Japanese men aged 50-59 years between 2005 and 2010, including the 2008 global financial crisis. DESIGN: Prospective cohort study. SETTING: Randomly selected 2515 census areas from a total of 1.8 million census areas in Japan. PARTICIPANTS: This study utilised data from a national, longitudinal survey conducted by the Ministry of Health, Labour and Welfare. Starting in 2005, 16,738 Japanese men aged 50-59 years were recruited and sent a questionnaire each year. We analysed data for the 6-year period (2005-2010) from participants who had worked for over 20 years in the same industry (n=9727). MAIN OUTCOME MEASURES: We focused on worsening self-rated health status by occupation, education and employment contract. RESULTS: Working in the manufacturing industry was associated with worsening self-rated health scores when compared to those working in management (HR=1.19; 95% CI 1.04 to 1.37). A relationship between education level and worsening self-rated health was also identified as follows: junior high school (HR=1.49; 95% CI 1.31 to 1.69), high school (HR=1.29; 95% CI 1.17 to 1.42), and vocational college (HR=1.25; 95% CI 1.07 to 1.46), when compared with those holding university-level qualifications. Precarious employment (HR=1.17; 95% CI 1.00 to 1.37) was also associated with worsening self-rated health status in the current study. CONCLUSIONS: This study suggests that working in manufacturing for more than 20 years and having lower education levels may have a significant impact on the self-rated health of middle-aged Japanese men. This may reflect a progressive decline in Japanese working conditions following the global financial crisis and/or the impact of lower socioeconomic status.

Work Content and Serious Mental Illness among Middle-Aged Men: Results from a 6-Year Longitudinal Study in Japan.

OBJECTIVE: The present study aimed to determine prospective associations between work content after a working life of more than 20 years and serious mental illness among Japanese men aged 50 to 59 years, using a nationwide population-based survey. METHODS: Data were extracted from a national longitudinal survey of middle-aged and elderly persons previously conducted by the Ministry of Health, Labour and Welfare in Japan. We analyzed data across 10 work content categories for Japanese men who had been working in the same job type or industry for over 20 years. As part pf the survey, participants completed the Kessler (K)6 scale each year to determine their level of psychological distress (with scores ≥13 indicating serious mental illness). Cox discrete time proposal hazard regression analysis was used to examine potential associations between work content and serious mental illness from 2005 to 2010. Further adjustments were made for other sociodemographic characteristics and lifestyle factors. RESULTS: The current study involved a total of 11,942 participants with a mean (± standard deviation [SD]) of follow-up was 3.4 (± 2.0) years, during which time 892 participants (7.5%) had been classified as having a new-onset serious mental illness. Men who had worked in service jobs and in manufacturing jobs at baseline were more likely to develop serious mental illness than those in managerial jobs (hazard ratio 1.37, 1.30, 95% confidence intervals 1.04-1.80, 1.02-1.65) after adjustment for confounding variables. CONCLUSION: These findings suggest that Japanese men aged 50 to 59 years who have worked in service and manufacturing jobs after a working life of over 20 years have an increased risk of serious mental illness during follow-up. Identifying the most at-risk work content category after a working life of over 20 years would be an essential part of providing more effective interventions for psychological distress among Japanese men in this age group.