The 2011 Fukushima nuclear disaster affected workers at the Fukushima Daiichi Nuclear Power Plant. This study examined factors associated with long-term work motivation and the longitudinal association between work motivation and depressive symptoms over a three-year period. A total of 670 workers participated in annual surveys from 2012 to 2014. Work motivation and depressive symptoms were assessed using self-administered questionnaires, including the Center for Epidemiologic Studies Depression Scale (CES-D). Mixed-effects models were used to examine associations of background factors in 2011 with work motivation and depressive symptoms (CES-D score ≥16), as well as the relationship between work motivation and depressive symptoms. Higher long-term work motivation was associated with a sense of purpose toward work and local residents and perceived support from colleagues. Experience of discrimination or slurs was associated with increased work motivation over time. Higher baseline motivation was associated with a lower risk of depressive symptoms (OR=0.95, 95% CI: 0.93-0.96 in 2012; OR=0.96, 95% CI: 0.95-0.98 in 2013; OR=0.98, 95% CI: 0.96-0.998 in 2014). These findings highlight the potential importance of work motivation and emotional support in understanding occupational mental health during prolonged disaster recovery.
Schedule-setting arrangements and short-notice work requests may represent different dimensions of working-time quality. This cross-sectional study examined their associations with elevated insomnia symptoms among 25,783 employees aged 20-64 yr in the seventh Korean Working Conditions Survey. Four schedule-setting categories were retained; frequent short-notice requests occurred at least several times a month. Elevated symptoms were defined by a Minimal Insomnia Symptom Scale-based score ≥6. Type-appropriate multiple imputation and survey-weighted regression were used. Compared with company-set schedules, core-model prevalence ratios (PRs; 95% confidence intervals) were 1.24 (1.05-1.48) for fixed-schedule choice, 2.07 (1.72-2.49) for flextime within specified limits, and 1.29 (0.99-1.69) for full autonomy; frequent requests had PR 2.48 (2.05-3.01). In the most expanded model (n=25,780), flextime and frequent requests remained associated with elevated symptoms: PRs 1.59 (1.33-1.92) and 1.91 (1.59-2.30), respectively. Continuous-score findings were directionally consistent. These models estimate alternative conditional associations because added variables may be confounders or mediators. The findings support assessing schedule-setting arrangements and short-notice requests as distinct dimensions of working-time quality.
Chronic insomnia is common among truck drivers and is associated with an increased risk of road traffic accidents. However, evidence linking diet quality to insomnia in Japanese working populations remains limited. This cross-sectional study examined the association between adherence to the Japanese Food Guide (JFG) and chronic insomnia among 1,942 male Japanese truck drivers. Dietary intake was assessed using the Brief-type Diet History Questionnaire, and diet quality was evaluated using a modified JFG score. Chronic insomnia was defined according to ICSD-3. Chronic insomnia prevalence was 20.2%. In multivariable logistic regression analyses adjusting for sociodemographic, lifestyle, occupational and psychological factors, participants in the highest JFG adherence quartile had lower odds of chronic insomnia than those in the lowest quartile (OR 0.69, 95% CI 0.49-0.97, p=0.034). No significant associations were observed for the second or third quartiles, and the linear trend was not significant (p for trend=0.056). Psychological distress was the strongest factor associated with chronic insomnia, but no significant interaction with JFG adherence was observed. Greater adherence to the Japanese Food Guide remained independently associated with lower odds of chronic insomnia, suggesting that diet quality may complement workplace mental health strategies.
