Anticipated health effects and proposed countermeasures following the immediate introduction of telework in response to the spread of COVID-19: The findings of a rapid health impact assessment in Japan.

OBJECTIVES: The health effects of telework, which was introduced extensively in the immediate context of the COVID-19 pandemic crisis in Japan, on teleworkers, their families, and non-teleworkers, are unknown. Accordingly, we developed a rapid health impact assessment (HIA) to evaluate positive and negative health effects of telework on these groups and recommended easily implementable countermeasures. METHODS: Immediately after an emergency was declared in Japan, we implemented a rapid, five-step HIA. We screened and categorized health effects of telework for the three above-mentioned groups, extracting their content, directionality, and likelihood. Following a scoping exercise to determine the HIA's overall implementation, five experienced occupational health physicians appraised and prioritized the screened items and added new items. We outlined specific countermeasures and disseminated the results on our website. A short-term evaluation was conducted by three external occupational health physicians and three nurses. RESULTS: Following screening and appraisal, 59, 29, and 27 items were listed for teleworkers, non-teleworkers, and family members of teleworkers, respectively, covering work, lifestyle, disease and medical care, and home and community. Targeted countermeasures focused on the work environment, business management, communications, and lifestyles for teleworkers; safety and medical guidelines, work prioritization, and regular communication for non-teleworkers; and shared responsibilities within families and communication outside families for family members of teleworkers. CONCLUSION: The HIA's validity and the countermeasures' practical applicability were confirmed by the external evaluators. They can be easily applied and adapted across diverse industries to mitigate the wider negative effects of telework and enhance its positive effects.

Validity and responsiveness of the work functioning impairment scale (WFun) in workers with pain due to musculoskeletal disorders.

OBJECTIVE: To determine the convergent validity and responsiveness of the work functioning impairment scale (WFun) in workers with musculoskeletal disorder-related pain. METHODS: Participants were extracted from an internet user study and prospectively examined using the pain intensity numerical rating scale (pain-NRS), the work ability numerical rating scale (productivity-NRS), and the WFun at baseline, 2 weeks, 6 weeks, and 3 months. The convergent validity and responsiveness of the WFun were examined by multilevel regression analysis. RESULTS: A total of 786 workers participated and 593 completed all surveys. The WFun score gradually increased and decreased as the pain-NRS and the productivity-NRS increased, respectively. Changes in the WFun score steadily increased and decreased as changes in the pain-NRS and the productivity-NRS increased, respectively. Multilevel analyses showed that all linear associations were significant. CONCLUSIONS: The convergent validity and responsiveness of the WFun were consistent with the expected direction and magnitude.

Diagnostic Accuracy of the Work Functioning Impairment Scale (WFun): A Method to Detect Workers Who Have Health Problems Affecting their Work and to Evaluate Fitness for Work.

OBJECTIVE: This study evaluated the diagnostic accuracy of the Work Functioning Impairment Scale (WFun), a questionnaire to detect workers with health problems which affect their work, using an assessment by an occupational health nurse as objective standard. METHODS: The WFun was completed by 294 employees. The nurse interviewed to assess 1) health problems; 2) effects of health on their work; necessity for 3) treatment, 4) health care instruction, and 5) consideration of job accommodation. RESULTS: The odds ratio in the high work functioning impairment group compared with the low was highly statistically significant with 9.05, 10.26, 5.77, 9.37, and 14.70, respectively. The WFun demonstrated the high detectability with an area under the receiver operating characteristic of 0.75, 0.81, 0.72, 0.79, and 0.83, respectively. CONCLUSIONS: This study suggests that the WFun is useful in detecting those who have health problems affecting their work.

Prospective Cohort Study of Work Functioning Impairment and Subsequent Absenteeism Among Japanese Workers.

OBJECTIVE: This study examined the association of work functioning impairment as measured by work functioning impairment scale (WFun) and subsequent sick leave. METHODS: A prospective cohort study was conducted at a manufacturer in Japan, and 1263 employees participated. Information on sick leave was gathered during an 18-month follow-up period. RESULTS: The hazard ratios (HRs) of long-term sick leave were substantially increased for those with a WFun score greater than 25 (HR = 3.99, P = 0.003). The incidence rate ratios (IRRs) of days of short-term absence gradually increased as scores of WFun increased (IRR = 1.18, P < 0.001 in the subjects with WFun of over 25 comparing with those with WFun of 14 or less). CONCLUSIONS: Assessing work functioning impairment is a useful way of classifying risk for future sick leave among employees.

Evaluation and simplification of the occupational slip, trip and fall risk-assessment test.

OBJECTIVE: The purpose of this investigation is to evaluate the efficacy of the occupational slip, trip and fall (STF) risk assessment test developed by the Japan Industrial Safety and Health Association (JISHA). We further intended to simplify the test to improve efficiency. METHODS: A previous cohort study was performed using 540 employees aged ≥50 years who took the JISHA's STF risk assessment test. We conducted multivariate analysis using these previous results as baseline values and answers to questionnaire items or score on physical fitness tests as variables. The screening efficiency of each model was evaluated based on the obtained receiver operating characteristic (ROC) curve. RESULTS: The area under the ROC obtained in multivariate analysis was 0.79 when using all items. Six of the 25 questionnaire items were selected for stepwise analysis, giving an area under the ROC curve of 0.77. CONCLUSION: Based on the results of follow-up performed one year after the initial examination, we successfully determined the usefulness of the STF risk assessment test. Administering a questionnaire alone is sufficient for screening subjects at risk of STF during the subsequent one-year period.

Development and validity of a work functioning impairment scale based on the Rasch model among Japanese workers.

OBJECTIVES: The purpose of this study was to develop a new work functioning impairment scale (WFun) and examine its validity. METHODS: The WFun was developed based on the Rasch model, which consists of seven items. We conducted a pilot study (n=1,000) using an Internet investigation and a field study (n=1,294) in a manufacturing industry, and we additionally collected data from six workplaces from other industries. This series of studies was examined with a Rasch model analyses including item fit statistics as well as hypothesis testing. Convergent validity was used to examined the association of the WFun with the Stanford Presenteeism Scale, SF-8, Work Ability Index, and several types of job disruptions. We also examined differential test functioning. RESULTS: All the items showed adequate fit (infit mean-square statistics <1.5). The item reliability was 0.98, and the item separation index was 6.37. The person reliability was 0.86, and the person separation index was 2.32. All tests for convergent validity showed significant differences. All p values derived from ANOVA were highly significant (p<0.001). No differential test function was observed between groups by age, sex, or job type or between various samples from different workplaces. The intraclass correlation of the estimated Rasch measurements from these groups was 0.99 (95% CI: 0.976-0.992). CONCLUSIONS: The WFun was confirmed to show good fit to a Rasch model and construct validity. Given that its good fit indicates specific objectivity, this tool will be useful in assessing the ability of individuals to function at work and in evaluating group levels for benchmarking.

An industry-based cohort study of the association between weight gain and hypertension risk among rotating shift workers.

OBJECTIVES: We investigated whether the association between shift work and hypertension is independent of weight gain. METHODS: Subjects were 10,173 male employees (9209 daytime workers, 964 three-shift workers; mean follow-up period: 12.7 years). Hypertension was defined as systolic blood pressure 140 mm Hg or more or diastolic blood pressure 90 mm Hg or more. The risk of developing hypertension among shift workers was estimated using a Cox proportional hazards model with adjustment for several factors. RESULTS: Analysis revealed that "shift work" (hazard ratio [HR]: 1.85; 95% confidence interval [CI]: 1.68, 2.03), "baseline body mass index" (HR: 1.13; 95% CI: 1.12, 1.15), and "increase in body mass index during follow-up" (HR: 1.15; 95% CI: 1.13, 1.17) were significant independent risk factors for hypertension. CONCLUSIONS: Shift work is a significant risk factor for hypertension that is independent of both starting weight and weight gained over years of work.

A cross-sectional study of workplace social capital and blood pressure: a multilevel analysis at Japanese manufacturing companies.

OBJECTIVES: We examined the contextual effect of workplace social capital on systolic blood pressure (SBP). DESIGN: Cross-sectional. SETTING: A conglomerate from 58 workplaces in Japan. PARTICIPANTS: Of the 5844 workers at a Japanese conglomerate from 58 workplaces, 5368 were recruited. Individuals who received drugs for hypertension (n=531) and who lacked information on any variable (n=167) were excluded from the analyses, leaving 4735 individuals (3281 men and 1454 women) for inclusion. PRIMARY AND SECONDARY OUTCOME MEASURES: Systolic blood pressure. RESULTS: The contextual effect of workplace social capital on SBP was examined using a multilevel regression analysis with a random intercept. Coworker support had a contextual effect at the workplace level (coefficient=-1.97, p=0.043), while a lack of trust for coworkers (coefficient=0.27, p=0.039) and lack of helpfulness from coworkers were associated with SBP (coefficient=0.28, p=0.002). CONCLUSIONS: The present study suggested that social capital at the workplace level has beneficial effects on SBP.

Retrospective cohort study of the risk of impaired glucose tolerance among shift workers.

OBJECTIVES: The aim of this study was to investigate the effect of shift working on the risk of developing impaired glucose tolerance (IGT). METHODS: This study comprised 6413 male employees (5608 daytime workers, 512 3-shift workers and 293 2-shift workers) whose work schedules remained constant during the follow-up period (mean follow-up period 9.9 years). IGT was defined as Hemoglobin A1c ≥ 5.9%. The Cox proportional hazards model was used to estimate the risk of developing IGT, after making adjustments for age, smoking, alcohol consumption, leisure-time physical activity, body mass index (BMI) and Hemoglobin A1c (HbA1c) at baseline. Analysis was additionally performed for a sub-cohort of 1625 workers with BMI of 20.0-25.0 kg/m² that did not change by >2.0 kg/m² during the follow up period. RESULTS: The risk of developing IGT was significantly elevated among both 3-shift workers [hazard ratio (HR) 1.78, 95% confidence interval (95% CI) 1.49- 2.14] and 2-shift workers (HR 2.62, 95% CI 2.17-3.17). Significant elevations of the risk were still observed at the additional analysis on the sub-cohort (3-shift work: HR 3.55, 95% CI 2.02-6.25; 2-shift work: HR 4.86, 95% CI 2.62-9.01). CONCLUSIONS: Both 2- and 3-shift workers were associated with a high risk factor of developing IGT compared to day workers. Moreover, 2-shift workers had a higher risk than 3-shift workers. The risk was observed even among workers whose body mass remained within the normal range.

[Practical use of DPC information for occupational health consultation].

BACKGROUND: The Diagnosis Procedure Combination (DPC) is a national administrative case-mix classification system for acute inpatient care which was launched in Japan in 2003. This system was designed to increase the standardization and transparency of medical information. The system has collected medical information in a unified format nationwide from acute hospitals. Significant parts of the data has been published by Ministry of Health, Labour and Welfare, including average length of hospital stay and number of patients by disease and hospital. This information is valuable for medical consultation in occupational health settings. OBJECTIVES: This article provides an overview of the DPC system and how to utilize the data from the perspective of occupational health practitioners.

Industry-based retrospective cohort study of the risk of prostate cancer among rotating-shift workers.

OBJECTIVES: The risk of prostate cancer among shift workers was examined in the present industry-based retrospective cohort study. METHODS: The study was established based on a health-care database from a Japanese manufacturing corporation. Work schedules of 4995 male workers (mean age = 55.5 years) were followed up retrospectively; mean follow-up period = 25.0 years. Of the subjects, 4168 had previously undertaken only daytime work (daytime workers), whereas 827 had undertaken rotating three-shift work for >80% of their career (shift workers). All subjects had undergone prostate-specific antigen (PSA) testing. Prostate cancer incidence data were obtained from the health insurance records of 13 daytime and four shift workers. Multivariate logistic regression was used to estimate the relative risk of prostate cancer for the two groups with adjustments for age, body mass index, alcohol intake, smoking, exercise and marital status. RESULTS: Compared with daytime workers, shift workers showed a non-significant increase in the risk of prostate cancer (odds ratio = 1.79; 95% confidence interval = 0.57, 5.68; P-value = 0.32). CONCLUSIONS: Some increase in the risk of prostate cancer for shift workers was observed, although the result was not statistically significant as a result of the small number of cases. To identify the prostate cancer risk among shift workers, longer-term follow up, including the period after retirement, is required.

Retrospective cohort study of the risk of obesity among shift workers: findings from the Industry-based Shift Workers' Health study, Japan.

OBJECTIVES: The authors investigated the effect of shift working on the risk of obesity using data from the Industry-based Shift Workers' Health (IbSH) study, a retrospective cohort study based on a health care database system belonging to a manufacturing corporation in Japan. METHODS: The study database contains data on annual health check-ups and work schedules for every worker in the corporation in Japan since 1981. Study subjects consisted of 9912 male employees (8892 daytime workers and 920 rotating three-shift workers; mean age at first check-up was 23.7 years) whose work schedules were consistent during the follow-up period. Obesity was defined as a body mass index ≥ 25.0. RESULTS: 3319 cases of obesity were recorded over the 27.5 years of retrospective follow-up. Kaplan-Meier survival analysis visually demonstrated an increased risk of obesity among shift workers. The risk becomes particularly obvious after 10 years of follow-up. Cox proportional-hazards model analysis revealed a significantly increased risk among shift workers (RR 1.14, 95% CI 1.01 to 1.28). CONCLUSION: The risk of obesity among male shift workers was visually and statistically demonstrated.

[Health impact assessment of occupational health policy reform at a multinational chemical company in Japan].

A health impact assessment (HIA) was conducted to identify potential health impacts arising from policy reform of occupational health and safety at S-chemical company, a multinational global company that employs about 13,000 workers. A multidisciplinary team of health professionals including occupational physicians, an epidemiologist, and public health researchers oversaw the HIA. A project manager from S-company was also involved in the whole HIA process. A literature review, profiling using annual health examination data and interviews with stakeholders and key informants were undertaken in order to identify possible impacts. A range of positive and negative health impacts were identified and develop recommendations for implementation of the new occupational health policy were proposed. The HIA added value to the planning process for the occupational health policy reform.

Anxiety about starting three-shift work among female workers: findings from the Female Shift Workers' Health Study.

In 1999, the Japanese Law on Equal Employment Opportunity and Conditions was amended and the previous prohibition of the assignment of female workers to night work was abolished. Subsequently, the number of female shift workers has been increasing in Japan, necessitating greater attention to the health care of this population. The aim of the current study is to evaluate the relationship between anxiety expressed about starting three-shift work and background characteristics among female workers who were being assigned to three-shift work for the first time. The subjects were 38 middle-aged female workers (age range: 44 to 59 years) who were working at a chemical plant. The women completed a self-administered questionnaire before starting three-shift work. Levels of anxiety about starting three-shift work were assessed by the question 'Do you feel anxious about starting three-shift work?' The available responses were: 'Very agree', 'Considerably agree', 'Rather agree', 'Slightly agree' and 'Not agree at all', and 63% of the subjects gave one of the first two answers, which were defined as indicating anxiety. We also acquired information regarding lifestyle and occupation for each subject, including the following factors: frequency of breakfast consumption, subjective sleep insufficiency, previous experience of similar work before beginning shift work, previous experience of two-shift work, and responsibility for household duties. In the study, we found a marginally statistically significant trend association between frequent breakfast consumption and anxiety about starting three-shift work (P(trend) = 0.09). Anxiety was also high among subjects with sleep disorders, especially those suffering from subjective sleep insufficiency (P = 0.08). Due to the small study population, these results should be interpreted with caution and confirmed by future studies.