Both fatigue and negative work-life balance can be influenced by job characteristics and individual differences, while fatigue is associated with reduced positive well-being. This paper reports a study that investigated the mediation effect of fatigue between those stressors and well-being outcomes among UK railway staff. A large number of significant mediation effects of fatigue were found in this study, and as a result, the process by which job demands, job support and control influence major positive well-being outcomes can be partially explained by fatigue.
Fatigue is a daily experience among people in the workforce. In the railway industry, fatigue is a serious issue due to the heavy workload, long working hours, and shiftwork. Failure to manage the train crew’s fatigue may result in an increased risk to train safety and employees’ well-being. The stressors causing occupational fatigue include either job characteristics or personal characteristics [
Cameron [
Therefore, Mark and Smith [
Our previous work among train crew found that job characteristics predict work-life balance and well-being (both at work and outside work) as well as occupational fatigue [
This study aims to examine the relationship that job and personal characteristics have with fatigue, negative work-life balance, and positive well-being, both at work or outside work. It was hypothesised that fatigue was the mechanism through which job characteristics and individual differences would affect well-being outcomes, thus acting as a mediating variable (as shown in
Participants were recruited from one of the train companies in the United Kingdom. Their job roles included conductors, train drivers, station workers, engineers, administrators, managers, at-seat catering stewards, and controllers.
This survey ran from 27 April to 18 May, 2015. The well-being questionnaire used in the present study was the Smith Well-being Questionnaire (SWELL), which included26 single-item questions from the Wellbeing Process Questionnaire (WPQ) [
Based on the DRIVE model and WPQ, the items in this survey included individual characteristics, job characteristics, fatigue, and well-being outcomes. The section on job characteristics included job demands, job control and support, working environment (levels of noise and fumes), and whether participants worked in shifts. The section on well-being included positive well-being (i.e., job satisfaction, happiness at work, life satisfaction, and happiness outside work) and work-life balance. Most of the questions were rated on a 10-point scale, and the remaining were Yes/No answers (e.g., “Do you do shift-work?”).
Data analysis was carried out using SPSS 23 software. The independent variables tested were workload, job control and support, shift work, exposure to noise and vibration, exposure to fumes, health-related behaviours (or health lifestyle), and personality. The dependent variables tested were fatigue, negative work-life balance, and positive well-being outcomes. Hayes’ [
A total of 1067participants completed the questionnaires (N = 1067, mean (±SD) age = 44.25 ± 10.763 yr.), with a response rate of around 50%. The most common job types were conductors (25.9%), train drivers (22.6%), and station workers (21.3%). Of the participants, 58.3% rated their fatigue as high (threshold = 6), and the fatigue problem was apparent in all the job roles mentioned. In addition, 74.9% of the participants did shiftwork.
The association between predictors, fatigue, and well-being outcomes was investigated using the Pearson correlation. High job demands showed a significant correlation with fatigue (r (1061) = .43, p < 0.01), negative work-life balance (r (1059) = 0.31, p < 0.01), and positive well-being outcomes (r from -0.19 to -0.07, p < 0.01). Other negative job characteristics, such as shiftwork, exposure to noise, and exposure to fumes, were also significantly correlated with fatigue and negative work-life balance, with correlation coefficients between .30 and .43 and all significant to p < 0.01.No significant correlation was found between shiftwork, work exposure to noise or fumes, and the well-being outside work.
A higher level of job control and support showed a significant negative correlation with a higher level of fatigue and poorer work-life balance (r from -0.25 to -0.27; p < 0.01). It was also correlated with positive well-being (r from 0.13 to 0.62, p < 0.01). In addition, positive personal characteristics, such as positive personality and healthy lifestyle, showed a positive correlation with positive well-being outcomes (r from 0.14 to 0.62, p < 0.01), and a small but significant negative correlation with fatigue and negative work-life balance (r from -0.15 to -0.10, p < 0.01).
Fatigue showed a significant correlation with negative work-life balance, r (1061) = 0.48, p < 0.01, with a high level of fatigue associated with poor work-life balance. Fatigue showed a significant negative correlation with the positive well-being outcomes, both in general life and at work, including life satisfaction, job satisfaction, life happiness, and work happiness (r from -0.23 to -0.30, p < 0.01).
Hayes Mediation was used to examine whether fatigue mediated the effects of job characteristics and individual differences on well-being outcomes. The variables used in this analysis were original scores, in which shiftwork was the categorical variable, and the rest were continuous variables. Fatigue was found to mediate the impacts of these variables on most of the well-being outcomes. The indirect effect was tested using a bootstrap estimation approach with 1000 samples [
Fatigue was found to mediate the impacts of lifestyle and personality on work-life balance and positive well-being outcomes (shown in
The relationships between job demands, job support and control, and outcomes were mediated by fatigue (
Y | X: Positive Lifestyle | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Life Satisfaction | 0.27*** | [0.21, 0.33] | 0.25*** | [0.19, 0.31] | 0.03 | [0.01, 0.04] | |
Life Happiness | 0.22*** | [0.17, 0.28] | 0.20*** | [0.15, 0.25] | 0.02 | [0.01, 0.04] | |
Job Satisfaction | 0.16*** | [0.09, 0.22] | 0.13*** | [0.06, 0.19] | 0.03 | [0.01, 0.05] | |
Job Happiness | 0.18*** | [0.12, 0.24] | 0.15*** | [0.09, 0.20] | 0.04 | [0.02, 0.05] | |
Neg. Work-Life Balance | ?0.14* | [?0.23, ?0.05] | ?0.05 | [?0.13, 0.03] | ?00.08 | [?0.13, ?0.04] | |
* p < 0.05; ** p < 0.05; *** p < 0.05. B = unstandardised coefficient; CI = confidence interval.
Y | X: Positive Personality | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Life Satisfaction | 0.60*** | [0.54, 0.65] | 0.57*** | [0.52, 0.63] | 0.0245 | [0.02, 0.04] | |
Life Happiness | 0.60*** | [0.56, 0.65] | 0.58*** | [0.54, 0.63] | 0.0225 | [0.01, 0.04] | |
Job Satisfaction | 0.47*** | [0.40, 0.53] | 0.44*** | [0.37, 0.51] | 0.0305 | [0.02, 0.05] | |
Job Happiness | 0.47*** | [0.41, 0.53] | 0.43*** | [0.38, 0.49] | 0.0388 | [0.02, 0.06] | |
Neg. Work-Life Balance | ?0.24*** | [?0.33, ?0.14] | ?0.13* | [?0.22, 0.05] | ?0.1077 | [?0.15, 0.06] | |
* p < 0.05; ** p < 0.05; *** p <0.05. B = unstandardised coefficient; CI = confidence interval.
Y | X: Job Demands | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Life Satisfaction | ?0.08** | [?0.13, ?0.02] | 0.02 | [?0.04, 0.07] | ?0.09 | [?0.12, ?0.07] | |
Life Happiness | ?0.07** | [?0.12, ?0.02] | 0.02 | [?0.03, 0.07] | ?0.09 | [?0.12, ?0.07] | |
Job Satisfaction | ?0.15*** | [?0.20, ?0.09] | -0.06 | [?0.12, 0.01] | ?0.09 | [?0.12, ?0.05] | |
Job Happiness | ?0.18*** | [?0.23, ?0.12] | ?0.07* | [?0.13, ?0.02] | ?0.10 | [?0.13, ?0.08] | |
Neg. Work-Life Balance | 0.41*** | [0.34, 0.49] | 0.17*** | [0.10, 0.25] | 0.24 | [0.19, 0.30] | |
* p < 0.05; ** p < 0.05; *** p < 0.05.B = unstandardised coefficient; CI = confidence interval.
mediate the impact of job demands on life happiness, life satisfaction, and job satisfaction, with the direct effect reduced to non-significance, indicating full mediation. Fatigue was also found to mediate the impact of job demands on work-life balance and job happiness (i.e., happiness at work), with partial
Y | X: Job Support and control | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Life Satisfaction | 0.40*** | [0.35, 0.45] | 0.37*** | [0.31, 0.42] | 0.03 | [0.02, 0.05] | |
Life Happiness | 0.36*** | [0.31, 0.40] | 0.32*** | [0.28 0.37] | 0.03 | [0.02 0.05] | |
Job Satisfaction | 0.55*** | [0.50, 0.60] | 0.52*** | [0.47, 0.57] | 0.03 | [0.01, 0.05] | |
Job Happiness | 0.53*** | [0.48, 0.57] | 0.49*** | [0.44, 0.57] | 0.04 | [0.03, 0.06] | |
Neg0. Work-Life Balance | ?0.37*** | [?0.45, ?0.29] | ?0.22*** | [?0.30, ?0.15] | ?0.15 | [?0.20, ?0.11] | |
* p < 0.05; ** p < 0.05; *** p < 0.05. B = unstandardised coefficient; CI = confidence interval.
mediation. The effect of job support and control on negative work-life balance and positive well-being were partially mediated by fatigue. These mediation effects were considered to be significant, as the confidence interval of indirect effects did not contain zero.
The results showed that fatigue partially mediated the impact of shift work on negative work-life balance. The total effect of demand on efficiency was 1.57 (C.I = 1.19, 1.95, p < 0.001), with a direct effect of demand on efficiency of 1.19 (CI = 0.85, 1.53, p < 0.001). The indirect effect was 0.39, and the confidence interval was 0.22 to -0.58, which was significant. No mediation was found between shift work and the other outcomes because those relationships were non-significant (p of total effect > 0.5).
Fatigue partially mediated the influences of noise and fumes on negative work-life balance (see
The individual scores for fatigue and predictors used in the following analysis were categorised as high or low using median split. For example, fatigue (M = 6, range = 1 to 10) scores above the median were categorised as “high fatigue,” while the others were categorised as “low fatigue”. Eta-squared (η²) in ANOVA was used to compare the effects size of the predictor variables on the outcomes for the high/low fatigue groups. Cohen [
It was predicted that the beneficial effects of positive predictors would be smaller in the high fatigue group. For example, as
Y | X: Exposure to noise | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Job Satisfaction | ?0.05* | [?0.09, ?0.01] | ?0.01 | [?0.05, ?0.03] | ?0.04 | [?0.05,?0.03] | |
Job Happiness | ?0.06* | [?0.09, ?0.02] | ?0.01 | [?0.05, 0.03] | ?0.05 | [?0.06,?0.03] | |
Neg0. Work-Life Balance | 0.21*** | [0.16, 0.26] | 0.11*** | [0.06, 0.16] | 0.10 | [0.08, 0.13] | |
* p < 0.05; ** p < 0.05; *** p < 0.05. B = unstandardised coefficient; CI = confidence interval.
Y | X: Exposure to fumes | M: Fatigue | |||||
---|---|---|---|---|---|---|---|
Total Effects | Direct Effects | Indirect Effects | |||||
B | CI | B | CI | B | CI | ||
Job Satisfaction | ?0.06** | [?0.10, ?0.02] | ?0.02 | [?0.06, ?0.02] | ?0.04 | [?0.05, ?0.02] | |
Job Happiness | ?0.07** | [?0.11, ?0.03] | ?0.02 | [?0.06, 0.01] | ?0.04 | [?0.06, ?0.03] | |
Neg0. Work-Life Balance | 0.24*** | [0.19, 0.29] | 0.15*** | [0.10, 0.19] | 0.09 | [0.07, 0.12] | |
* p < 0.05; ** p < 0.05; *** p < 0.05.B = unstandardised coefficient; CI = confidence interval.
Mean (SD) | High Fatigue | Low Job Fatigue | ||
---|---|---|---|---|
High Job Support and Control | Low Job Support and Control | High Job Support and Control | Low Job Support and Control | |
Life Happiness | 7.92 (1.54) | 7.03 (1.73) | 8.61 (1.17) | 7.27 (1.78) |
Life Satisfaction | 7.85 (1.66) | 6.76 (1.92) | 8.34 (1.44) | 7.08 (1.90) |
Job Happiness | 8.06 (1.41) | 6.52 (2.06) | 8.79 (1.12) | 6.99 (1.79) |
Job Satisfaction | 8.18 (1.55) | 6.64 (2.09) | 8.79 (1.41) | 6.80 (2.14) |
Neg. Work-Life Balance | 6.70 (2.70) | 7.29 (2.24) | 4.08 (2.51) | 5.62 (2.58) |
SD = Standard Deviation.
negative outcome (negative work-life balance) in the low fatigue group compared to those with high fatigue.
The results showed that the effect size of job support and control on all of the five well-being outcomes and the effect of job demands on work-life balance (η2low fatigue group = 0.04; η2high fatigue group = 0.02) as larger in the low fatigue group than in the high fatigue group. In the low fatigue group, the effect size of job supports and control, calculated using eta squared was large on job happiness (η2low fatigue group = 0.29: η2high fatigue group = 0.15), job satisfaction (η²low fatigue group = 0.24: η2high fatigue group = 0.14), and life happiness (η2low fatigue group = 0.17; η2high fatigue group = 0.07), and it was medium on life satisfaction (η2low fatigue group = 0.13: η2high fatigue group = 0.08), with all η2 larger than those in the high fatigue group. Besides, the effect sizes of individual differences were larger in low fatigue group than in high fatigue group. For personality, the effect size was large on life happiness (η2low fatigue group= 0.34: η2high fatigue group = 0.15) and life satisfaction (η2low fatigue group = 0.25: η2high fatigue group = 0.12). It was medium on job happiness and in job happiness in low fatigue group, which is still larger than in high fatigue group. For healthy behaviours, the effect size on the well-being outcomes was also larger in low fatigue group than in high fatigue group. The effect size of other predictor variables was not very different between high/low fatigue groups.
The mediation effects found in this study are in line with what the DRIVE model proposed [
The correlation results showed that fatigue was significantly related to work-life balance and well-being, in both daily life and work life, included life satisfaction, life happiness, job satisfaction, and happiness at work. Job characteristics and personal characteristics were also significantly associated with fatigue and the outcomes, as previous studies have shown [
In the mediation analysis, fatigue was found to mediate the effects of individual differences and work characteristics on negative work-life balance and most of the positive well-being outcomes. In which case, full mediation effects of fatigue were found between lifestyle and negative work-life balance; between job demands and life happiness, life satisfaction, and job satisfaction; and between work environment (noise and fume) and well-being at work. This means that essentially all the relationships between the above variables were via the mediated or indirect pathway. Therefore, when considering the indirect pathway, the direct relationship becomes non-significant. For shiftwork, fatigue mediated its impact on negative work-life balance, meaning that shift-work increased fatigue, which then resulted in poor work-life balance. No significant direct effect was found for shiftwork on other well-being aspects. Noise and fumes in the workplace did not directly affect life satisfaction and life happiness.
The difference of outcomes between the high and low predictor groups (e.g., high/low support and control) was found bigger in the low fatigue group which was mainly because high fatigue removes the benefit of positive predictors. When compared the effect of the predictor variables on the outcomes for the high/low fatigue groups, the effect size of job supports and control and individual differences on positive well-being, and job demands for negative work-life balance was found larger in the low fatigue group. This indicated that high fatigue reduced the effect of predictors. In other words, there was the direct effect in the low fatigue group, while there were both the direct and indirect effect in the high fatigue group. These results supported the mediating role of fatigue between the predictors and well-being outcomes.
Overall, a large number of significant mediating effects of fatigue on the relationships between stressors and well-being outcomes were found, meaning that the hypothesis can be accepted. Thus, the results essentially support the enhanced DRIVE model.
This study examined the mediation effect of fatigue on the influences that job and personal characteristics have on negative work-life balance and positive well-being among UK railway staff. The results suggest that job characteristics and individual difference affect work-life balance and well-being, and that these effects can be mediated by fatigue. As a result, the process by which job demands influence positive well-being could be explained by fatigue. The results also provide support for the enhanced DRIVE model that fatigue was a mechanism through which job demands, job support, and control could affect well-being outcomes. In future studies, a healthy lifestyle can be considered as an intervention to decrease fatigue and, thus, improve work-life balance.
The authors would like to acknowledge the participants in the study for their support and assistance.
Fan, J.L. and Smith, A.P. (2018) The Mediating Effect of Fatigue on Work-Life Balance and Positive Well-Being in Railway Staff. Open Journal of Social Sciences, 6, 1-10. https://doi.org/10.4236/jss.2018.66001