Introduction: Excessive sedentary behaviour has been identified as a significant risk factor for physical health. However, the evidence concerning its impact on mental health is less consistent. While some studies suggest a detrimental association between total daily sedentary time and mental health, a growing body of inconsistent findings challenges this consensus, indicating that the relationship may be more complex and that not all forms of sedentary behaviour are equally harmful. Given that the workplace is a primary setting for extended daily sedentary periods, investigating the potential influence of occupational sedentary behaviour on mental health is therefore critical. The Software and Information Technology (IT) industry in China is a large and rapidly growing workforce, characterised by predominantly computer-based work and a culture driven by efficiency. Consequently, employees in this sector are likely to spend substantial amounts of time being sedentary, and such inactivity could place them at risk of adverse physical and mental health outcomes. Crucially, there is a dearth of research that has specifically measured or collected data on their duration of occupational sedentary time. Concurrently, the absence of corresponding tailored intervention development for this population means both the scale of the problem and potential solutions remain unknown. Therefore, the overarching aim of this PhD research project was to develop evidence-based and theory-informed intervention strategies for Software and IT workers in China. The primary focus was on reducing occupational sedentary behaviour, while ensuring that implications for mental health remained a key consideration throughout the development of intervention strategies. Methods: A systematic review and a two-phase explanatory sequential mixed-method design were conducted to achieve the overarching aim. The systematic review collated existing evidence and utilised the “Best-Evidence Synthesis” approach to determine the association between occupational sedentary behaviour and mental health symptoms among office workers. Phase 1 of the mixed-method study was a cross-sectional survey to: 1) examine the duration of total and occupational sedentary behaviour and the level of mental health symptoms among Software and IT workers in China; 2) determine the association between occupational sedentary behaviour and common mental health symptoms; and 3) identify variables that may influence the association between occupational sedentary behaviour and common mental health symptoms. Phase 2 of the mixed-method study was a qualitative study to: 1) explore the barriers and facilitators of reducing occupational sedentary behaviour among Chinese Software and IT workers; and 2) understand Software and IT workers' perspectives on how occupational sedentary behaviour may influence their mental health. To inform the intervention recommendations, a weaving and joint display method were used to integrate findings from both phases. Results: The systematic review showed mixed findings among office workers, with both positive and null associations between occupational sedentary behaviour and common mental health symptoms, suggesting insufficient evidence for a clear association. The Phase 1 cross-sectional study found that Software and IT workers reported a mean occupational sedentary time of 427.9 (±133.2) minutes, while their total daily sedentary time reached 499.9 (±161) minutes on workdays. Occupational sedentary time accounted for 72.4% of working hours, equivalent to 347.52 minutes in an 8-hour day. The mental health outcomes indicated that Software and IT workers generally experienced low levels of perceived stress, while their average scores for depression and anxiety suggested a tendency towards mild symptom levels. Hierarchical regressions revealed that neither total or occupational sedentary behaviour showed a statistically significant association with depression or anxiety after adjusting for all potential confounding variables. However, total sedentary behaviour was significantly associated with stress. Occupational sedentary behaviour initially demonstrated a statistically significant association with stress, but the observed relationship between occupational sedentary behaviour and stress disappeared following adjustment for occupational variables (e.g., daily working hours, tenure, and job satisfaction) and poor sleep quality. Path analysis demonstrated that poor sleep quality potentially mediates the indirect effect of occupational sedentary behaviour on stress. Longer tenure was identified as a confounding variable, demonstrating a negative association with both occupational sedentary behaviour and stress. The Phase 2 qualitative study identified four themes capturing key factors influencing occupational sedentary behaviour, including barriers, facilitators, or both: (1) Industry-Driven Prolonged Sedentary Behaviour; (2) Company Influence on Occupational Sedentary Behaviour; (3) Automatic and Reflective Motivation to Reduce Occupational Sedentary Behaviour; and (4) Influence of Socialisation on Occupational Sedentary Behaviour. Three themes were identified to understand Software and IT workers' perspectives on how occupational sedentary behaviour may influence their mental health: (1) Physical Discomfort from Sedentary Work; (2) Pace of Software and IT Work; and (3) Beliefs about Occupational Sedentary Behaviour. Conclusion: By employing a systematic review and an explanatory sequential mixed-methods design, several objectives were achieved through this programme of study: a better understanding of the relationship between occupational sedentary behaviour and mental health; the identification of factors influencing occupational sedentary behaviour in the Software and IT workplace in China; and the proposal of potential intervention strategies based on empirical and integrated findings. These findings contribute to the growing body of sedentary behaviour research and highlights the need for future research and practice. The thesis proposes that this could include exploring the mechanism between reducing sedentary behaviour and mental health outcomes; tailoring the intervention development in the workplace setting by taking into account the specific occupational characteristics of the target population; and discussing the potential for policy to mitigate the overtime culture that contributes to prolonged workplace sedentary behaviour. Future research and practice in Chinese workplaces can use the findings in this thesis as a basis for refining the intervention development.
Ming Jin (Thu,) studied this question.