A Prospective Assessment of the Relationships between Workplace Stress, Trait Mindfulness and Physiological Indices of Stress in Direct-care Workers: A Mixed- methods Investigation with a Mindfulness-based Intervention

Submission note: A thesis submitted in total fulfilment of the requirement for the degree of Doctor of Philosophy to the School of Psychological and Public Health, College of Science, Health and Engineering, La Trobe University, Victoria, Australia.

Thesis with publications.

The public version of this thesis does not contain all material submitted for examination.

The effort-reward imbalance (ERI) and job demands-resources (JD-R) workplace stress models have been used to predict poor health. However, it is unclear to what extent personal characteristics (e.g. trait mindfulness, empathy, overcommitment) play a role in these models. This research aimed to determine the effectiveness of mindfulness-based intervention (MBI) and assessed relationships between workplace stress, dispositional characteristics, and physiological indices of the stress response. A systematic review with meta-analysis and a qualitative study were used to inform the subsequent stages of the research. The systematic review synthesized the literature on workplace-based MBI and found that day-time cortisol secretions and heartrate-variability may be most impacted by these programs. The focus groups identified job demands, rewards and job resources that were not captured in the generic questionnaires for each model. Empathy, good communication, and resiliency were identified as potential personal resources. An 8-week, online MBI was conducted. The findings demonstrated that the program induced short-term improvements in fatigue and anxiety. Following the program, employees reported decreased overcommitment, and increased trait mindfulness, optimism, and mucosal immunity (secretory immunoglobulin A [sIgA]). The final two empirical studies prospectively assessed the relationship between workplace stress, dispositional characteristics, and physiological indices of stress and ill health. Changes in ERI, job demands, and job resources were not associated with changes in the awakening responses of cortisol and salivary alpha amylase (sAA) or sIgA. However, higher trait mindfulness was associated with increased sIgA. Further, increased empathy and job resources both independently buffered the relationship between higher job demands and a larger sAA awakening response. This dissertation highlights through systematic review and empirical investigation, that MBI may not necessarily improve perceptions of job stress but may improve coping, which leads to desirable changes in physiological markers of stress and/or ill-health.