OBJECTIVES:To identify and synthesize evidence on the applications of infrared thermography in the assessment of work-related conditions and to examine its contribution as a non-invasive, adjunctive, and complementary tool to support multidisciplinary clinical assessment and decision-making in occupational health. METHODS:A systematic review with narrative synthesis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement and was registered in the International Prospective Register of Systematic Reviews. Nine bibliographic databases were searched without date or language restrictions. Critical appraisal used Joanna Briggs Institute tools selected according to study design. RESULTS:Database searches identified 317 records, and seven additional reports were identified through other methods. Forty-nine studies published from 1975 to 2025 were included. Infrared thermography characterized thermal patterns, monitored occupational exposures and physiological responses, documented changes following interventions or across assessed conditions, and contributed to exploratory screening or predictive models. Applications addressed peripheral vascular responses to cold and vibration, musculoskeletal loading, heat stress, fatigue and drowsiness, respiratory protection, and emerging computational technologies. Observational designs predominated, with heterogeneous protocols and several small or convenience samples. No included study was classified as a diagnostic accuracy study. CONCLUSIONS:Overall, infrared thermography was used primarily as a non-invasive, adjunctive, and complementary imaging method to document skin-surface temperature distribution and thermal patterns in occupational contexts. When interpreted alongside occupational history and clinical, physiological, ergonomic, and environmental information, thermographic findings may contribute to multidisciplinary clinical assessment and decision-making. Methodological limitations and heterogeneity warrant caution when transferring findings across work-related conditions and occupational settings.
OBJECTIVES:To examine whether an online organizational intervention targeting managers in nursing homes could promote occupational health activities and reduce caregivers' low back pain. METHODS:This 6-month, prospective cluster randomized controlled trial was conducted between January and July 2024. Nursing homes in Fukuoka Prefecture, Japan were randomly assigned to an online program-intervention group (n=25) or an active control group (n=25). The intervention combined an original tool that comprised practical tips for the prevention of low back pain with a series of meetings delivered via an online meeting system. Caregivers' low back pain intensity was assessed as the primary outcome using a Numerical Rating Scale. Using the Japanese version of the Utrecht Work Engagement Scale, managers' work engagement was evaluated as a secondary outcome. Linear mixed models were applied under the intention-to-treat and per-protocol frameworks. RESULTS:A total of 48 managers and 449 caregivers working in the facilities were included in the final analysis. Over the 6-month study period, no significant differences were observed between the intervention and active control groups in caregivers' low back pain intensity or managers' work engagement. Participation in the intervention among managers was moderate (61.1%), and only six managers attended all the intervention session (adherence rate: 25%). CONCLUSIONS:Online organizational interventions targeting nursing homes did not significantly improve caregivers' low back pain or work engagement. High job demands, suboptimal adherence, and constraints inherent in the videoconference system potentially attenuated the intervention's effects.Trial registration: UMIN Clinical Trials Registry (UMIN000051939).
OBJECTIVES:To characterize the implementation of ionizing-radiation health examinations at occupational health institutions in Japan and examine how these practices are implemented and interpreted within the current legal framework. We also identified operational factors that may influence their contribution to evaluating radiation-related health effects, fitness for work judgments, and occupational radiation protection. METHODS:A cross-sectional online questionnaire survey was conducted from January 28 to February 18, 2025, among member institutions listed in the National Federation of Industrial Health Organization directory. Invitations were mailed to 173 institutions, each designating a respondent knowledgeable about examination implementation. Descriptive results were summarized using item-specific denominators and stratified by annual examination volume. RESULTS:In total, 90 institutions responded, of which 89 provided ionizing-radiation health examinations. Exposure history was primarily obtained through worker self-report, with limited use of employer documentation or dose records. Lens examinations mainly relied on visual inspection or penlight examination; slit-lamp examination was rare, and retro-illumination imaging was not reported. Skin examinations almost exclusively used unaided visual inspection. Institutions differed in diagnostic classification frameworks and whether personal dose information informed judgment. CONCLUSIONS:Implementation varied across institutions, particularly in exposure assessment and the use of personal dose information in clinical judgment. This heterogeneity may limit not only the interpretability of examination results but also their contribution to evaluating radiation-related health effects, fitness for work judgments, and occupational radiation protection. These findings highlight the importance of improving the availability and integration of exposure-related information within existing examination processes, particularly in predominantly low-dose occupational environments.
BACKGROUND:Construction workers face substantial occupational heat exposure, but little is known about whether heat-related symptoms form distinct co-occurring profiles or which modifiable workplace and behavioral factors characterize workers with greater symptom burden. This study used latent class analysis (LCA) to identify heat-related symptom profiles among construction workers and examine associated behavioral and workplace factors. METHODS:This cross-sectional study analyzed data from 357 construction workers at 7 South Korean worksites in September 2022. Participants reported heat-related symptoms experienced during the preceding summer (June-August 2022). LCA was performed using 4 binary indicators: dizziness, headache, heat sensation, and near-accident experience. Factors associated with class membership were examined using R3STEP multinomial logistic regression. RESULTS:A 2-class model provided the best fit (entropy = 0.878), identifying a high-symptom class (29.4%) and a low-symptom class (70.6%). Work persistence tendency was most strongly associated with high-symptom class membership, followed by fatigue severity. Rest break guidance and chronic disease status were inversely associated with membership; the latter association may reflect selection effects among currently employed workers. Rest break practice was positively associated with membership, though this association warrants cautious interpretation given the cross-sectional design. CONCLUSIONS:Nearly one-third of workers belonged to a high-symptom class with co-occurring heat-related symptoms. High-symptom class membership was more strongly associated with behavioral and workplace factors than with individual characteristics. The inverse association with organizational rest break guidance highlights the need for institutional protocols that authorize stopping work before symptoms develop. These findings support organizational interventions that reduce reliance on worker-initiated prevention.
OBJECTIVES:This study examined the relationship between employment quality and workers' health and well-being in China. METHODS:Data were drawn from the 2018, 2020, and 2022 waves of the China Family Panel Studies. We constructed an individual-level panel sample and measured employment quality using 4 dimensions: reward, job satisfaction, working-time quality, and social security. Individual fixed-effects models were used as the main estimation approach. Robustness checks were conducted using a balanced panel sample and an alternative employment quality index excluding the job satisfaction dimension. RESULTS:Higher employment quality was positively associated with better self-rated health, mental health, happiness, and confidence in the future. Among the 4 dimensions, job satisfaction showed the most consistent positive associations with all 4 outcomes, whereas reward and working-time quality were mainly associated with mental health. Social security did not show statistically significant associations in the fixed-effects models. In the robustness check excluding job satisfaction, the coefficients of the alternative employment quality index remained positive but became smaller and less statistically significant; only the association with mental health remained statistically significant. CONCLUSIONS:Workers' health and well-being were related not only to employment status or income, but also to broader aspects of employment quality, including subjective work experience, working-time arrangements, and institutional protection. Employment quality and its different dimensions should receive greater attention in occupational health promotion and the evaluation of high-quality employment.
OBJECTIVES:Home workspace ergonomics may influence telework-related somatic symptoms; however, evidence regarding interventions promoting teleworkers' self-directed environment setup remains limited. We examined the effects of a behavioral science-based educational intervention on telework environment setup behaviors and somatic symptoms among Japanese employees. METHODS:This was a secondary analysis of the TELEWORK cluster randomized controlled trial (UMIN000053861). Workplace departments were randomized as clusters (1:1) to intervention/control. The 12-week program comprised educational emails, short videos, individualized feedback sheets, and supportive supervisor messages. The primary and secondary outcomes were the Telework Environment Setup Behavior (12 items) and Somatic Symptom Scale-8 (SSS-8) scores, respectively. Analyses used a modified intention-to-treat approach with mixed-effects models. RESULTS:Twelve clusters from 6 companies participated (182 and 188 in the intervention and control groups, respectively). No significant between-group differences were observed in environment setup (difference, 1.34; 95% CI, -1.67 to 4.35; P = .345) or SSS-8 (difference, -1.10; 95% CI, -2.59 to 0.38; P = .129) scores at follow-up. In the process evaluation, over half of intervention participants who completed the follow-up reported satisfaction, nearly 90% read the emails, and approximately 40% viewed the videos. Among video viewers, approximately two-thirds reported adopting recommended behaviors, while >80% rated the content useful. CONCLUSIONS:This secondary analysis did not detect statistically significant improvements in telework environment setup behaviors or somatic symptoms. Statistical conclusions regarding intervention effects remain inconclusive, underscoring the need for organizationally supported, multifaceted strategies to strengthen telework environments.
OBJECTIVES:Presenteeism is commonly assessed using retrospective instruments such as the World Health Organization Health and Work Performance Questionnaire (WHO-HPQ); however, how daily presenteeism assessed using experience sampling relates to these standard measures remains unclear. This study quantified within-person variability in daily presenteeism assessed using experience sampling methods (ESMs) among Japanese workers, while also examining its convergence with retrospective WHO-HPQ presenteeism. METHODS:This observational study enrolled 94 white-collar employees; 93 were included in the final analysis after exclusion of 1 participant because of missing data. Participants completed daily work performance assessments on 19 weekdays using a mobile-based ESM approach. Aggregated daily presenteeism scores were compared with retrospective WHO-HPQ presenteeism scores assessed over the preceding 4 weeks. Convergence was evaluated using Spearman rank correlation coefficient, and agreement was examined using Bland-Altman analysis. Within-person variability was quantified using the coefficient of variation (CV) and intraclass correlation coefficient (ICC). RESULTS:Mean daily absolute presenteeism scores were strongly correlated with retrospective WHO-HPQ presenteeism scores (Spearman rs = 0.783, P < .001). Bland-Altman analysis showed minimal systematic differences on average, despite substantial individual-level variability. Daily presenteeism exhibited substantial variability, with a CV of 42.2% (95% CI, 36.7-47.6) and an ICC of 0.431. CONCLUSIONS:Daily presenteeism converged with retrospective WHO-HPQ presenteeism while capturing substantial within-person variability that is not fully reflected in retrospective assessments. These findings support interpreting presenteeism as a dynamically fluctuating state and highlight the importance of selecting measures with appropriate temporal resolution.
OBJECTIVES:Computer vision syndrome (CVS) is increasingly recognized as an occupational health issue in workplaces with heavy digital use. Although there is ample evidence among IT professionals and students, data on administrative staff in public health care is scarce. This research aimed to determine the prevalence of CVS and identify related factors among administrative workers in public health care facilities on Malaysia's east coast. METHODS:A cross-sectional study involving 370 administrative workers from 6 government health care institutions was carried out using multistage random sampling. Data collection included a validated Computer Vision Syndrome Questionnaire and ergonomic assessments. Multiple logistic regression and mixed-effects logistic regression analyses were used to determine independent predictors of CVS. RESULTS:The prevalence among participants was 59.7%. Key independent predictors included being female (adjusted odds ratio [aOR] = 2.05; 95% CI, 1.21-3.46), poor horizontal eye level positioning (aOR = 2.27; 95% CI, 1.40-3.70), and wearing corrective glasses (aOR = 1.84; 95% CI, 1.13-2.99). CONCLUSIONS:CVS was common among administrative workers in public health care facilities in the east coast state of Malaysia. Modifiable ergonomic factors, especially incorrect screen positioning, greatly raised the risk. These results emphasize the importance of workplace ergonomic interventions and regular visual health checks to reduce digital eye strain and enhance occupational health in settings with extensive computer use.
OBJECTIVES:Collaboration between occupational health nurses and human resources (HR) personnel is essential in supporting the return to work of employees with mental health problems. However, the factors influencing this collaboration are unclear, and this study therefore aimed to examine these factors. METHODS:A cross-sectional questionnaire survey was conducted among 3049 occupational health nurses from the Japan Society for Occupational Health, and responses from 528 participants were analyzed. Collaboration was measured using the Japanese version of the Relational Coordination Survey (J-RCS). Independent variables included individual factors relating to both occupational health nurses and HR personnel, relational factors, workplace climate factors, and organizational justice. Structural equation modeling was used to examine associations with J-RCS scores. RESULTS:The mean J-RCS score was 3.58 (SD = 0.79), indicating a moderate level of collaboration. Structural equation modeling showed that relational factors (β = .75, P < .001) and organizational justice (β = .40, P = .003) had significant direct effects on collaboration. Individual factors relating to occupational health nurses or HR personnel, and workplace climate factors, showed no direct effects but contributed indirectly through associations with other factors. The model explained 88.8% of the variance in J-RCS scores. CONCLUSIONS:Enhancing the quality of relationships, including trust and information sharing, and improving organizational justice, are crucial for strengthening collaboration in support for return to work. This study provides practical intervention targets and useful insights for improving occupational health policies and practices.
OBJECTIVES:Pediatric surgeons often experience physical and psychological strain. However, surgery may provide motivation and fulfillment. To explore this dual nature of surgical work, we examined physiological and psychological stress responses of pediatric surgeons on surgical working days (SWs) and nonsurgical working days (NSWs). METHODS:Nineteen pediatric surgeons participated in this cross-sectional study. Salivary cortisol, autonomic nervous activity using a wearable device (low/high heart rate ratio [LHR]), and total mood disturbance (TMD) score, calculated from subscales of the Profile of Mood States 2nd Edition (POMS2) as an index of mood state, were assessed at 2 time points: before and after surgery by the operator on SWs (mean preoperative time: 11:16 am; mean postoperative time: 2:18 pm) and at 8:00 am and 5:00 pm on NSWs. Data were analyzed using mixed linear models and univariate tests to evaluate the influence of sex, post-call status, experience, and surgical site. RESULTS:On both SWs and NSWs (54 and 44 evaluation sessions from 19 pediatric surgeons, respectively), the post-work decrease in cortisol levels was smaller on SWs than on NSWs (P < .05). LHR increased significantly after surgery (SWs) but not on NSWs (P < .05), indicating a sympathetically activated state, particularly remarkable in post-call status compared with non-post-call status (P < .05). TMD scores were lower on SWs than on NSWs (P < .05), reflecting improved mood during surgical activity. More experienced surgeons (>5 years) had lower TMD scores for both SWs and NSWs (P < .05). CONCLUSIONS:Despite physical and psychological demands, performing surgery was linked to reduced mood disturbance among pediatric surgeons.
OBJECTIVES:Building on the previous descriptive study of work productivity across various diseases among Japanese workers, this additional analysis aimed to assess the associations between multimorbidity and work productivity, as well as independent associations between each disease and work productivity, accounting for coexisting diseases. METHODS:From the original study population of the secondary dataset derived from health insurance claims and online surveys, including workers aged ≥19 years who completed the Work Productivity and Activity Impairment questionnaire-General Health (WPAI-GH) in an online survey in 2021, we analyzed participants aged <65 years (n = 30 953). The association of a WPAI score >0% with diseases count and each target disease adjusted for other diseases was explored using logistic regression, and the predicted probabilities of having a score >0% for each disease were derived. RESULTS:The odds ratios (ORs) for having a WPAI score of >0% increased (OR > 1) per additional disease. Associated with higher odds of having a score >0% were, in males, migraine, depression, dysthymia, diarrheal disorders, and insomnia; and in females, migraine, insomnia, and atopic dermatitis. Femoral neck fracture, dysthymia, depression, migraine, and menopausal disorder in males, and migraine and ischemic heart disease in females were among the top diseases with high predicted probabilities. CONCLUSIONS:Each incremental disease was significantly associated with impaired work productivity. After adjusting for other comorbidities, work productivity impairment was associated with psychiatric disorders and migraines. These findings underscore the importance of optimal management of preexisting conditions and prevention of comorbidities.
BACKGROUND:Nurse resignation is a major issue in global health care systems. Nurses experience health problems due to irregular night shift work and excessive work demands. This study investigated the association between initial factors at the start of employment and the early resignation of newly employed nurses at 2 university hospitals. METHODS:This study conducted a prospective follow-up of 641 new nurses for 6 months. Data on sleep problems, depression, anxiety, and stress-related factors were collected during job orientation. Early resignation was defined as voluntary resignation within 6 months of starting work. Multiple logistic regression analysis was conducted to identify significant factors. RESULTS:The mean age of participants was 23.7 years, and most were female (86.6%). During the 6-month follow-up, 243 nurses (37.9%) resigned. Nurses who resigned early were slightly older and reported higher baseline levels of perceived stress, depression, and anxiety, as well as fewer stress relievers. Early resignation was also more frequent among participants with perceived socioeconomic vulnerability (PSV). In adjusted analyses, high perceived stress (adjusted odds ratio [aOR], 2.203; 95% CI, 1.088-4.459; P = .028) and PSV (aOR, 1.622; 95% CI, 1.162-2.264; P = .005) remained independently associated with early resignation. Depression and fewer stress relievers were associated with early resignation in crude analyses. CONCLUSIONS:Voluntary early resignation was more common among newly employed nurses who reported high perceived stress and PSV before starting work. High perceived stress and PSV served as independent predictors of early resignation, while depression and limited stress-relief resources may represent additional potential risk factors during the early transition period. Early stress assessment, mental health-oriented support, and tailored educational interventions for new nurses may help to reduce early resignation rates.
OBJECTIVES:To investigate the association between occupational health nurse (OHN) involvement and Bright 500 certification, an indicator of high-performing health and productivity management (HPM), among Japanese small- and medium-sized enterprises (SMEs) using multi-year survey data. METHODS:This observational study used secondary data from the 2021-2024 HPM Survey. Each annual response was analyzed as a corporation-year observation, and within-corporation correlation was handled with a random intercept for corporations. OHN involvement was defined as the appointment of public health nurses and/or nurses as health promotion officers. Bright 500 certification, obtained from publicly available certification records, was used as an indicator of more advanced HPM. The association was examined using a mixed-effects logistic regression model. RESULTS:The analytical sample comprised 12 847 (2021), 14 401 (2022), 17 316 (2023), and 20 267 (2024) SMEs. OHN involvement increased from 5.1% (2021) to 5.8% (2024). Bright 500 certification was consistently higher in corporations with OHN involvement (10.8% in 2021, 8.4% in 2024) than in those without (2%-3% across years). After adjustment for survey year, region, insurer category, industry type, employee size, internal and external dissemination of HPM initiatives, and occupational physician involvement, OHN involvement was independently associated with certification (odds ratio: 2.35; 95% CI, 1.21-4.54; P = .011). CONCLUSIONS:Across the 4 survey waves, OHN involvement was positively associated with Bright 500 certification among SMEs. These findings suggest that OHNs may be relevant to advanced HPM implementation in this setting. Future studies should capture OHN staffing arrangements, intensity and roles, and initiative timing to clarify mechanisms and potential causality.
OBJECTIVES:The roles of dichloromethane (DCM) and 1,2,3-trichloropropane (1,2,3-TCP) in occupational cholangiocarcinoma, first reported in 2012, remain elusive. This study aimed to determine the potential of 1,2-dichloropropane (1,2-DCP), DCM, and 1,2,3-TCP to induce DNA damage-a hallmark of carcinogenicity-in human cholangiocytes. METHODS:Monocultures of human immortalized cholangiocytes (MMNK-1 cholangiocytes) and co-cultures of MMNK-1 cholangiocytes with human THP-1 monocyte-derived macrophages and monocytes were each exposed to 1,2-DCP, DCM or 1,2,3-TCP at 0, 0.1, and 0.4 mM for 24 hours. DNA double-strand break marker γ-H2AX-positive foci and γ-H2AX pan-nuclear staining-which is known to be induced during early or intermediate stages of apoptosis or under replicative stress/checkpoint abrogation in cholangiocytes-were counted in 100 and 200 cholangiocytes, respectively. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. RESULTS:The increase in dense (≥55) γ-H2AX foci induced by all 3 chemical compounds was significantly greater in co-cultures with macrophages, but not with monocytes, than in monocultures. However, only 1,2-DCP decreased the number of γ-H2AX pan-nuclear-positive and TUNEL-positive cholangiocytes in co-cultures with macrophages, but not in monocultured cholangiocytes. Co-treatment with a pan-caspase inhibitor decreased the number of γ-H2AX pan-nuclear-positive cholangiocytes in each group by about 50%, suggesting that apoptotic signaling is involved, at least in part, in the induction of γ-H2AX pan-nuclear-positive cholangiocytes. CONCLUSIONS:Our study showed that co-culture with macrophages enhanced DNA double-strand breaks induced by all 3 tested chemical compounds, while only 1,2-DCP exhibited a proliferative effect in monocultures and anti-apoptotic effects in co-cultures with macrophages, which are key characteristics of carcinogens, thus distinguishing 1,2-DCP from DCM and 1,2,3-TCP.
OBJECTIVES:Submarine environments pose unique challenges to maintaining physical activity due to space constraints, operational demands, and prolonged confinement. This review aims to synthesize existing literature on the health and performance consequences of reduced physical activity in submarine personnel and to examine feasible strategies to mitigate these effects during deployment. METHODS:A narrative overview methodology was adopted, with peer-reviewed studies identified from PubMed, Scopus, and Google Scholar. Articles examining physical activity patterns, health outcomes, and exercise or movement-based interventions in submarine environments and comparable confined operational settings were included. RESULTS:Submarine deployments are consistently associated with reduced physical activity, low step counts, and limited opportunities for structured exercise. Prolonged inactivity during deployment may contribute to unfavorable changes in body composition, including increases in fat mass, potential reductions in muscle mass, and in some contexts, alterations in bone health. Collectively, these changes may increase longer-term cardiometabolic and musculoskeletal risk, particularly with repeated deployments. Practical, low-burden strategies such as increasing daily movement, no-load or bodyweight resistance exercise, and minimal-dose eccentric-focused training appear feasible within submarine constraints and may help preserve health and physical function. CONCLUSIONS:Maintaining physical health during submarine deployments requires proactive, context-specific approaches compatible with the operational environment. Low-resource exercise strategies that emphasize maintenance of activity, rather than performance optimization, may provide a practical means of mitigating health and performance declines during deployment. Further research is needed to determine the long-term effectiveness and implementation of these approaches in submarine populations.
OBJECTIVES:This study aimed to develop a method for measuring airborne concentrations of tert-butylphenols (tert-BPs) to assess workers' occupational exposure. METHODS:Air samples were collected using an XAD-7 sorbent tube. tert-BPs were desorbed from the sorbent with methanol, and their concentrations in the desorbed solutions were determined via high-performance liquid chromatography with fluorescence detection. Method validation included evaluation of retention efficiency, storage stability, method quantitation limit, and reproducibility. RESULTS:The retention efficiencies for 2-tert-BP, 3-tert-BP, and 4-tert-BP in the XAD-7 sorbent tube were 89%-97%, 93%-96%, and 95%-96%, respectively. Relative standard deviations, reflecting the overall reproducibility of the proposed method, ranged from 0.5% to 5.9% for all tert-BPs. tert-BPs remained stable on the XAD-7 sorbent tube for at least 7 days at 4°C. The method quantitation limit was 0.118 μg/sample for each tert-BP. CONCLUSIONS:The developed method provides a robust and reproducible approach for assessing occupational exposure to airborne tert-BPs, enabling accurate determination within a concentration range of 0.8-160 ppb. This method can facilitate more precise risk assessments in occupational environments.
OBJECTIVES:Prolonged reduced heart rate variability (HRV) is associated with impaired health and chronic diseases. Despite this connection, it remains unclear which psychosocial job demands are the strongest predictors of reduced HRV and poorer health outcomes. This study aimed to determine the most relevant psychosocial job demands that predict reduced HRV. METHODS:The study participants were 163 municipal employees (86% female, mean age 47) who responded to a survey on psychosocial job demands and measured their electrocardiography-based HRV over 4 consecutive nights during a normal work week. The root mean square of successive RR intervals (RMSSD) was used as an indicator of autonomic nervous system activity mediated by the vagus nerve. Hierarchical mixed model regression analysis included psychosocial job demands and the most relevant individual factors and occupational sector as a nested random effect. Dominance analysis (DA) was used to assess all the variable combinations to identify the most significant determinants of HRV across the regression models. RESULTS:The participants' RMSSD was stable over the measurement period. DA ranked the participants' age as the factor that most affected RMSSD. The psychosocial job demands that seemed to be the most relevant for RMSSD were encountering bullying and violence at work, ethically challenging situations at work, and effort-reward imbalance. Gender was ranked as the fourth factor. CONCLUSIONS:These results need to be confirmed in further studies, but they suggest that workplace bullying and violence as well as ethically challenging situations at work might have the greatest effect on HRV among public sector employees.
OBJECTIVES:Participatory organizational interventions (POIs) may improve workers' mental health and work performance, but evidence from systematic reviews and meta-analyses of cluster-randomized controlled trials (cRCTs) remains limited. The meta-analysis has not been updated since it was published in 2015; a previous study focused on health care workers; and potential outcomes have not been adequately examined. This systematic review and meta-analysis aimed to investigate the effects of POIs on mental health and work performance among workers. METHODS:The current study searched PubMed, EMBASE, PsycINFO, PsycARTICLES, and Japan Medical Abstracts Society for papers published up until November 11, 2022. Eligible studies were cRCTs assessing the effects of POIs on mental health or work performance. The risks of bias were evaluated by using the Cochrane risk-of-bias tool for cRCTs and meta-analysis was performed using a random effects model. RESULTS:Fourteen cRCTs were included in the systematic review, and 8 cRCTs in the meta-analysis. The meta-analysis showed a nonsignificant beneficial effect on mental health conditions [standardized mean difference (SMD) = -0.04; 95% CI, -0.10 to 0.03], positive mental health (SMD = -0.004, 95% CI, -0.077 to 0.068), and work performance (SMD = 0.01; 95% CI, -0.10 to 0.13). CONCLUSIONS:This study did not confirm that POIs had a statistically significant effect on mental health or work performance. However, several studies that reported favorable results tended to emphasize active and structured participation, alignment with workers' needs, and attention to organizational context. Further research is needed to identify the conditions under which the interventions are effective.
