Industrial Health
Online ISSN : 1880-8026
Print ISSN : 0019-8366
ISSN-L : 0019-8366
Advance online publication
Displaying 1-20 of 20 articles from this issue
  • Kosuke SAKAI, Tomohisa NAGATA, Takahiro MORI, Naozumi SUEYOSHI, Shunsu ...
    Article ID: 2024-0081
    Published: 2024
    Advance online publication: July 11, 2024

    This study aims to determine the factors that encourage older workers to continue working. This study had an exploratory sequential design using a mixed-methods approach, including interviews and questionnaire surveys. In the interview survey, we targeted 30 workers aged between 60–65 across three manufacturing companies. After using the results of the content analysis in the interviews, we conducted an online questionnaire survey with 1,500 workers aged between 60–89 across the country. We analyzed whether the 15 factors were related to intention to continue working using logistic regression analysis. We identified factors affecting job continuity from three perspectives: individual, company, and life. We determined several factors: health condition, job performance, self-esteem, conservatism, employment system, workload, medical insurance and welfare programs, monetary and non-monetary rewards, relationships, attachment to the organization, distance between living and work, social support, economic situation, and employment policy. In the questionnaire survey, some factors had no relationship with job continuity, including conservatism, employment systems, monetary rewards, and the distance between living and work. Employers and policymakers can use the findings to consider appropriate ways of supporting older workers.

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  • Hiroki IKEDA, Tomohide KUBO, Shuhei IZAWA, Nanako NAKAMURA-TAIRA, Toru ...
    Article ID: 2024-0069
    Published: 2024
    Advance online publication: July 10, 2024

    Daily rest period (DRP) refers to the interval between the end of one workday and the start of the next. This study examined the joint association of DRP and sleep duration with subsequent sick leave among Japanese daytime employees. Participants (n=5,593) were measured for DRP and sleep duration at baseline and for sick leave at 1-year follow-up. They were categorized into 10 groups based on their DRP and daily sleep duration. Logistic regression analyses for individuals experiencing sick leave for longer than a month showed that the combination of short DRP (<11 h) and sleep duration (<6 h) had a higher odds ratio (4.981, 95% confidence interval [CI] = 1.126–22.046) than the reference group. Furthermore, the combination of short DRP and normal sleep duration had a higher odds ratio (8.152, 95% CI = 1.801–36.902) than the reference group. Short DRP was associated with subsequent long sick leave.

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  • Article ID: 2024-0093
    Published: 2024
    Advance online publication: July 04, 2024
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  • Mihoko MORI, Yoshitaka MORIMATSU, Tatsuya ISHITAKE
    Article ID: 2023-0165
    Published: 2024
    Advance online publication: June 25, 2024

    To investigate factors contributing to the mental health of Vietnamese technical intern trainees in the food manufacturing industry, a questionnaire survey was conducted twice with a six-month interval. A total of 111 technical trainees who participated in two surveys were included in the analysis. We used a mixed-effects model, where items with statistically significant associations in the univariate analysis were fixed effects, factories were random effects, and the outcome was defined as the K6 score at follow-up. The mean K6 score increased from 3.13 (SD 3.5) at baseline to 3.86 (SD 4.1) at follow-up, with 26.1% and 34.2% exhibiting poor mental health (K6≥5) at baseline and follow-up, respectively. Insomnia and years of training experience were significantly associated with the K6 score at follow-up. Those with insomnia had significantly higher K6 score at follow-up. Compared to the first year of training, K6 score at follow-up increased significantly for training in their third year or more. It is important to understand the sleeping conditions of trainees and support them based on their years of training experience.

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    Article ID: 2023-0114
    Published: 2024
    Advance online publication: June 06, 2024

    Workplace violence is a significant problem in industry, especially among rank-and-file workers, known as “blue-collar workers”. This systematic review and meta-analysis aim to evaluate the suitability of the reduced Negative Acts Questionnaire (NAQ-R) as an instrument to measure workplace violence in this type of population and synthesize the results of studies that have used it in different industrial sectors. A systematic review was conducted in accordance with the PRISMA 2020 statement. Publications describing populations of industrial workers were identified and included in the meta-analysis. For meta-analysis, we extracted data that allowed us to estimate the effect size of the included studies. We used a random-effects model to estimate the overall effect size and assessed heterogeneity between studies using the I² statistic. The global effect size test showed that the overall effect size was significantly different from zero (3.00, t=22.28, p<0.001), indicating an overall effect in relation to workplace violence measured by the NAQ-R in industrial workers. Our results support the claim that the NAQ-R is an effective tool for assessing workplace violence among industrial workers. These findings have important implications for practitioners and researchers working in the field of industrial psychology and occupational health.

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  • Benjamin Zhi Qiang SEAH, Seichi HORIE, Wee Hoe GAN, Chikage NAGANO, Al ...
    Article ID: 2024-0046
    Published: 2024
    Advance online publication: May 28, 2024

    This article aims to provide a historical overview of how workplace safety and health legislations in Singapore and Japan have evolved, and perform a comparative analysis of the occupational health systems where work-related medical examinations and health screening are concerned. The discourse is centered on three key themes – coverage, comprehensiveness, and continuity of care. The comparative analysis was performed based on secondary data obtained from open-source platforms. Singapore and Japan have robust workplace safety and health legislative frameworks and laws. However, their approaches diverge because of differing socioeconomic and political contexts. Japan's regulations are generally more comprehensive, require more frequent monitoring of workers' health status, and encompass both physical and mental health components. Singaporean companies focus primarily on the physical component of health, and statutory examinations are required only for exposure to specific occupational hazards. With increasing prominence of mental health issues and shift towards preventive care in Singapore, there will be greater emphasis on a holistic approach to each employee's overall health in future. For Japan, the challenge would be to strike a balance between long-term sustainability of current policies against the need for state and corporations to still retain an adequate stake in ensuring workers’ overall health.

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  • Toshiki KISHIMOTO, Yoshinori KITABATAKE, Takayuki TAGUCHI, Hiroaki NOB ...
    Article ID: 2023-0166
    Published: 2024
    Advance online publication: May 24, 2024

    Presenteeism has been noted to be associated with cognitive factors of pain, such as pain catastrophizing (PC) and pain self-efficacy (PS). Pain perception differs by gender, so it is important to consider gender differences when examining the association between cognitive factors of pain and presenteeism. This study aimed to examine the association between presenteeism and cognitive factors of pain, taking gender differences into account. A cross-sectional survey of 305 workers was conducted using a self-administered questionnaire that included items on pain status, PC, PS, and work performance. Multiple logistic regression analysis was used to test whether PC and PS independently influence presenteeism, separately for men and women. Logistic regression analysis showed that PC was extracted in men, and the group with severe PC had higher odds of presenteeism (odds ratio 6.56, 95%confidence interval [CI] 1.83–23.40). Contrarily, PS was extracted in women, with higher odds of presenteeism in the moderate (odds ratio 2.54, 95%CI 1.01–6.39) and low (odds ratio 5.43, 95%CI 1.31–22.50) PS groups than in the high PS. This study showed that the cognitive factors of pain related to presenteeism may differ by gender.

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  • Yuko OCHIAI, Yasumasa OTSUKA
    Article ID: 2023-0005
    Published: 2024
    Advance online publication: May 23, 2024

    This study aimed to investigate the validity and reliability of the Japanese version of the Overwork Climate Scale. Japanese workers were invited to participate in online surveys at baseline and 1-month follow-up. The Overwork Climate Scale was translated into Japanese, according to international guidelines. Reliability was assessed using Cronbach’s alpha and the intra-class correlation coefficient (ICC), while structural validity was evaluated through confirmatory factor analysis (CFA). Psychological job demands, work engagement, psychological safety, and workaholism were assessed for convergent validity. The number of respondents was 302 at baseline and 169 at follow-up. Results indicated robust Cronbach’s alpha values of 0.86 (for overwork endorsement) and 0.80 (for lacking overwork reward) at baseline, complemented by ICC of 0.89 and 0.82, respectively. CFA confirmed the suitability of the two-factor model. Moreover, the Japanese Overwork Climate Scale exhibited significant correlations with anticipated constructs. Structural equation modeling revealed a consistent association between overwork climate and both workaholism and work engagement, similar to the original version. In conclusion, the Japanese version of the Overwork Climate Scale demonstrates acceptable levels of reliability and validity, warranting its potential adoption among Japanese workers.

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  • Tianchang JI, May Young LOH, Jan DE JONGE, Maria C.W. PEETERS, Toon W. ...
    Article ID: 2024-0027
    Published: 2024
    Advance online publication: May 20, 2024

    Psychosocial safety climate (PSC) is defined as the corporate climate in relation to employees’ perceptions of organizational policies, procedures, and practices for the protection of employee psychosocial safety and well-being. The present study was based on the Demand-Induced Strain Compensation (DISC) Model and proposed that the interplay between identical job demands and resources would be conditioned by PSC. Particularly, high levels of PSC would enable employees to optimally perceive and utilize more job resources in dealing with corresponding job demands. A study was conducted among 406 Chinese workers from various occupational sectors. The findings of hierarchical regression analyses suggested that PSC a) mitigates the negative relation between emotional resources and exhaustion, b) enhances the positive relation between emotional resources and work engagement, and c) mitigates the negative relation between emotional demands and work engagement. We also found that PSC is a compensatory factor for low cognitive resources and demands encouraging high work engagement. Although we did not find the proposed three-way interactions, the present findings support the idea that high PSC is a fundamental contextual factor conducive to workers’ health and well-being, especially in perceiving and obtaining emotional resources.

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  • Ayako TAKATA, Hiroshi YAMAUCHI, Kiyotsugu YAMASHITA, Masahito AMINAKA, ...
    Article ID: 2024-0025
    Published: 2024
    Advance online publication: May 17, 2024

    Asbestos, especially chrysotile, continues to be exposed to humans globally. Hence, it should be disposed properly to prevent asbestos-related diseases, including mesothelioma and lung cancer. This study aimed to verify whether forsterite, a heating product of chrysotile, can cause carcinogenicity, particularly mesothelioma. Forsterite (FO-1000) and enstatite (EN-1500) produced by heating chrysotile at 1000°C and 1500°C, respectively, were subjected. We injected 10 mg of chrysotile, FO-1000, or EN-1500 in rats intraperitoneally and observed the development of peritoneal mesothelioma until 24 months. The incidence of peritoneal mesothelioma in the chrysotile group was 91.2%, whereas in the FO-1000 and EN-1500 groups, peritoneal mesothelioma did not develop. Urinary 8-hydroxy-2′-deoxyguanosine and serum N-ERC/mesothelin concentrations significantly increased in the chrysotile group that developed peritoneal mesothelioma, while they only temporarily changed in the FO-1000 or EN-1500 groups during early treatment. Furthermore, there was a significant homozygous deletion of the CDKN2A/p16 gene in the chrysotile group compared to the control group, in contrast to no significant difference in the FO-1000 and EN-1500 groups. Therefore, this study provides clear evidence that forsterite is a nonmesothelioma carcinogen and suggests that forsterite and enstatite are sufficient substances for chrysotile detoxification.

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  • Takashi SHIGENO, Takashi TATSUSE, Michikazu SEKINE, Masaaki YAMADA
    Article ID: 2023-0190
    Published: 2024
    Advance online publication: May 15, 2024

    Problem drinking causes a decline in labor productivity among working population. This study examined whether work characteristics, work–family status, and social activities are associated with future problem drinking behavior among Japanese civil servants. A total of 1,535 participants (men: 63.1%, women: 36.9%) with no problem drinking behavior were followed up from 2014 to 2019. A multivariable logistic regression analysis was performed to examine the factors associated with future problem drinking behavior. During the five-year follow-up period, the cumulative incidence of problem drinking was 9.6% and 5.8% in men and women, respectively. In both men and women, frequent drinking around three times a week or more and alcohol consumption of two units or more at baseline were associated with future problem drinking. In men, compared with low-grade employees, high-grade employees were less likely to become problem drinkers (OR: 0.56, 95% CI: 0.33–0.95). Shift workers were significantly associated with the incidence of problem drinking (OR: 2.96, 95% CI: 1.46–6.00). In women, poor own work performance was significantly associated with problem drinking (OR: 5.30, 95% CI: 1.57–17.86). In conclusion, disadvantaged work characteristics are associated with the development of problem drinking. To prevent problem drinking, attention should be paid to poor work characteristics.

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  • Chieko TAN, Kae MINEYAMA, Hideyuki SHIOTANI
    Article ID: 2023-0157
    Published: 2024
    Advance online publication: May 14, 2024

    The influence of night shift work on circadian heart-rate rhythm was examined in nurses engaged in shift work using a Holter electrocardiogram, continuously measured for two weeks, and cosine periodic regression analysis. We enrolled 11 nurses who were engaged in a two-shift system. The R2 value in the cosine regression curve of heart-rate rhythm (concordance rate), indicating the concordance rate between the actual heart rate over 24 h and the cosine regression curve approximated by the least-squares procedure, was significantly lower in the night shift (0.40 ± 0.15) than in the day shift (0.66 ± 0.19; p<0.001). Moreover, the amplitude was significantly lower and the acrophase was significantly delayed in the night shift. Thus, the circadian heart-rate rhythm was disrupted by the night shift work. Although the heart-rate acrophase recovered during the day and two days after the night shift, the concordance rate and amplitude did not recover, indicating that the influence of night shift work on circadian heart-rate rhythm might persist even two days after the night shift. Based on these results, adequate clinical attention should be paid to how to spend the day and two days after the night shift to correct the circadian heart-rate rhythm disruption caused by night shift work.

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  • Kyoko NAMIMATSU, Jun TAKEDA, Motoki ENDO, Yuito UEDA, Shintaro MAKINO, ...
    Article ID: 2023-0202
    Published: 2024
    Advance online publication: May 14, 2024

    This study was to investigate the employment status of pregnant women in Japan and identify risk factors associated with resigning from work during pregnancy. We conducted a cross-sectional survey with 975 postpartum women in Tokyo and its suburbs, focusing on those who were employed during pregnancy. Women who were employed when they became pregnant were selected and divided into two groups: those who did not resign and those who resigned; the groups were analyzed separately. Multiple logistic regression analyses were performed to examine associations between employment resignation and risk factors. The analysis revealed that 79% continued working, while 8.1% resigned. Risk factors for resignation included non-regular employment (OR: 13.1, 95% CI: 6.6–25.9), fewer employees (OR: 3.4, 95% CI: 1.8–6.4), and shorter employee tenure (OR: 2.4, 95% CI: 1.1–5.2). Non-regular employment status, a smaller number of employees, and shorter employee tenure were identified as risk factors for working women resigning from their job during pregnancy. In work situations and work environments that encourage pregnant women to leave the workforce, developing systems to improve these conditions for pregnant employees may help women to progress in the labor force.

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  • Madeline EVANS, Meagan E CROWTHER, Brandon W J BROWN, Sian WANSTALL, T ...
    Article ID: 2023-0135
    Published: 2024
    Advance online publication: May 10, 2024

    Paramedics commonly experience both poor sleep and mental health symptoms. Clarifying whether sleep or mental health symptoms are a challenge prior to commencement of employment is important, as early prevention and intervention initiatives during training could support these workers. Paramedicine students (n=53) were included, with sleep disorder screening (obstructive sleep apnea, insomnia and restless legs syndrome), and mental health outcomes (depressive symptoms: Patient Health Questionnaire-9, and anxiety symptoms: General Anxiety Disorder-7). Data were analysed using robust regression models, adjusted for age, sex, and shift work status. Meeting criteria for a sleep disorder (n=21) was associated with higher scores for anxiety (8.2 [95% CI: 5.9–10.5] v 4.6, [3.4–5.8]) and depressive symptoms (11.1 [8.6–13.6] v 4.4 [3.1–5.7)] compared to those who did not meet the criteria for a sleep disorder (n=32). Depressive symptoms were lower in those with perceived control over sleep (5.2 [3.2–7.2] v 9.8 [7.7–11.8]). There was no interaction between sleep disorder risk and perceived control over sleep on mental health symptoms. Investigation and management of factors contributing to low perceived control over sleep, together with early screening and management of sleep disorders, are likely to be important priorities to support paramedic student wellbeing prior to commencing shift work.  

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  • Mariann SANDSUND, Edvard AAMODT, Julie RENBERG
    Article ID: 2023-0151
    Published: April 17, 2024
    Advance online publication: April 17, 2024

    Firefighters risk heat strain during occupational tasks when exposed to extremely hot environmental conditions and performing high-intensity work. Relevant training scenarios are therefore essential. This study investigated the effect of a single simulated smoke dive and the following recovery phase on physiological and perceptual responses. Nineteen professional male firefighters (43 ± 8 yr) performed a 2-min stair walk and a15-min simulated smoke dive in a two-floor heat chamber (110 °C to 272°C) (HEAT), followed by a 5-min stair walk outside the heat chamber. Heart rate (HR), gastrointestinal temperature (Tgi) and skin temperatures were registered continuously during the test. The Tgi increased significantly from the start (37.5 ± 0.3°C) to the end of HEAT (38.4 ± 0.4°C) and further increased after the heat exposure (39.6 ± 0.5°C).The HR also increased significantly from the start (92 ± 14 bpm) to the end of HEAT (185 ± 13 bpm) and increased after the heat exposure to a maximum of 190 ± 13 bpm. The simulated smoke dive induced high physiological strain on the firefighters, and the increase in Tgi and HR after the hot exposure must be considered during live fire events when repeated smoke dives are required.

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  • Mediha ANNAÇ ASILDAĞ, Gülden SARI, Adem KOYUNCU, Ceprail ŞIMŞEK
    Article ID: 2023-0171
    Published: April 16, 2024
    Advance online publication: April 16, 2024

    Occupational exposure to manganese (Mn) primarily occurs through the inhalation of manganese-containing fumes and dust, with welding environments being significant sources of such exposure. Elevated levels of Mn in welding fumes can lead to a neurological syndrome known as manganism. A 28-yr-old male welder with 14 yr of experience, is presenting with complaints of forgetfulness, reasoning disorder, and decreased mental functions persisting for 10 yr. Three months ago, when he started working at the new workplace, he underwent employment screening conducted by the workplace physician. During this screening process, the physician identified a high whole blood Mn level of 25.9 µg/l. The diagnosis of manganism in this patient was established based on exposure to Mn and its compounds, high levels of Mn detected in the whole blood, hyperactive patellar reflexes observed during the physical examination, cranial Magnetic Resonance Imaging (MRI) findings consistent with manganism and complaints reported by the patient that are characteristic of manganism. In this report, the aim is to emphasize the significance of taking a comprehensive occupational history and to draw attention the potential health hazards associated with Mn and its compounds.

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  • Yushi MATSUURA, Kiyohide TOMOOKA, Hiroo WADA, Setsuko SATO, Motoki END ...
    Article ID: 2023-0174
    Published: April 16, 2024
    Advance online publication: April 16, 2024

    This cross-sectional study investigate the association between long working hours, short sleep duration, and mental health among Japanese physicians. We enrolled 232 Japanese physicians. We used the Brief Job Stress Questionnaire to assess high-stress status, and the Japanese version of the Center for Epidemiologic Studies Depression scale to assess depressive status. Daily sleep duration (DSD) and weekly working hours (WWHs) were collected using a self-administered questionnaire. Multivariable-adjusted logistic regression analysis was performed to examine the association of the combined categories of DSD and WWHs with high-stress and depressive status. Compared to physicians with WWHs <80 h and DSD ≥6 h, the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of high-stress status for those with WWHs ≥80 and DSD ≥6, WWHs <80 and DSD <6, and WWHs ≥80 and DSD <6 were 2.76 (0.97–7.87), 3.36 (1.53–7.40), and 3.92 (1.52–10.14), respectively. The respective ORs (CIs) of depressive status were 1.82 (0.42–7.81), 4.03 (1.41–11.53), and 4.69 (1.33–16.62). The results showed that regardless of working long hours or not, physicians with DSD <6 h had significantly higher stress and depressive status, suggesting that not only regulating long working hours but also ensuring adequate sleep duration is important for preventing physicians’ mental health.

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  • Yasuko OGATA, Miki SASAKI, Noriko MORIOKA, Mutsuko MORIWAKI, Yuki YONE ...
    Article ID: 2023-0184
    Published: April 08, 2024
    Advance online publication: April 08, 2024

    With the global nurse shortage, identifying nurse work environments that allow nurses to continue working is a common concern worldwide. This study examined whether a better nurse work environment (1) is associated with reducing nurses’ psychological distress; (2) reduces nurse resignations; (3) weakens the influence of psychological distress on their resignation through interaction effect; and (4) whether psychological distress increases nurse turnover. Multilevel logistic regression analyses were performed using data obtained in 2014 from 2,123 staff nurses from a prospective longitudinal survey project of Japanese hospitals. The nurse work environment was measured by the Practice Environment Scale of the Nursing Work Index (PES-NWI) consisting of five subscales and a composite, and psychological distress by K6. All the PES-NWI subscales and composite (ORs 0.679-0.834) were related to K6, significantly. Regarding nurse turnover, K6 had a consistent effect (ORs 1.834-1.937), and only subscale 2 of the PES-NWI had a direct effect (OR 0.754), but there was no effect due to the interaction term. That is, (1) and (4) were validated, (2) was partly validated, but (3) was not. As better work environment reduces K6 and a lower K6 decreases nurses’ resignation, high-level hospital managers need to continue improving the nurse work environment.

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  • Thomas E. BERNARD, Karl E. WILLIAMS, Candi D. ASHLEY
    Article ID: 2024-0015
    Published: April 03, 2024
    Advance online publication: April 03, 2024

    Assigning a value for metabolic rate is central to heat stress assessment. ISO 8996 describes a predictive method for walking based on the American College of Sports Medicine (ACSM) method and another generalized method based on average heart rate. In addition, the US Army uses the load carriage decision aid (LCDA) predictive equation to estimate metabolic rate. The purpose of this study was to assess the accuracy/bias and precision of the ISO heart rate method and the ACSM and LCDA equations. The laboratory database included metabolic rate, heart rate, treadmill speed, and grade during a progressive heat stress protocol. Treadmill speed and grade were set to represent one of three metabolic rates. Accuracy and precision were assessed with Bland-Altman plots. All three methods had good accuracy (low bias). For precision, the ISO heart rate method had a root mean square error (RMSE) of 34 W and 11% when adjusted for repeated measures. The RMSE for two equations was 20 W and 7%. Although the heart method had less accuracy, its application is more generalizable. The heart rate method should be used below the occupational exposure limit to avoid a bias toward higher predicted values due to heat strain.

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  • Sibylle GALLIKER, Tobias SCHMID, Martin GROSSE HOLTFORTH, Achim ELFERI ...
    Article ID: 2023-0183
    Published: March 29, 2024
    Advance online publication: March 29, 2024

    The study tested a brief intervention to stimulate and help supervisors reduce work-related interruptions among their employees, both at work and during leisure time. The core of the short-term intervention was a workplace analysis of work-related interruptions, which was fed back to supervisors in combination with a work redesign stimulation explaining why and how to reduce interruptions. Two intervention sessions, as one-on-one physical meetings, that lasted 1.5 h each and were 2 wk apart. The sample consisted of 20 managers and 89 employees. The non-experimental repeated measurement design comprised three questionnaire measurements of the 89 employees (two pre-measurements and one post-measurement). Repeated measure hierarchical linear models showed that the intervention significantly predicted reduced interruptions during work and work-related interruptions of leisure time. Although the intervention effect sizes were small, the current work design intervention with supervisors as mediating actors can reasonably contribute to occupational health prevention.

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