Browsing PhD e-theses by Subjects
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Development and evaluation of a tailored workplace intervention to reduce and break up sitting time in office workersThere is a growing body of evidence linking high volumes of sitting with adverse health risks, including cardiovascular disease and mental health problems. The workplace is a major contributor to excessive sitting, particularly for desk-based workers who spend more than two-thirds of working time sitting. Although the workplace contributes to prolonged sitting, it has also been identified as an ideal setting to combat sedentary behaviour (SB). A wide range of studies have sought to break up and reduce sitting time in the workplace using strategies like prompts to stand, environmental restructuring such as walking meetings and the use of active workstations. Although some of these strategies have been successful in decreasing workplace sitting time, results are inconclusive, with problems of compliance in some interventions. One reason for low compliance could be that few studies take views of employees into consideration when designing interventions. In addition, management might be reluctant to implement interventions if productivity is negatively affected. Finally, there is evidence that interventions developed to change behaviour should be informed by theoretical, evidence-based frameworks. Accordingly, the aim of this thesis was to design an appropriate intervention to break up and reduce workplace sitting time in desk-based office workers, then to test the efficacy of the intervention on employees’ productivity, cardiometabolic risks, and wellbeing. A multi-phase mixed-method study was employed covering the first two stages of the Medical Research Council framework for complex interventions. The first three phases covered the development of the subsequent intervention. Firstly, a systematic review found no acute effect of active workstations on productivity, although there were concerns regarding study designs and the tools used to assess productivity. Secondly, a cross-sectional study of self-reported sitting time found no differences between age, gender, and ethnic groups, suggesting that interventions to reduce workplace sitting should be targeted at all desk-based employees irrespective of age, gender, or ethnicity, although this need to be confirmed in a fully powered study. The final stage of the intervention development was a qualitative study of desk-based employees who had high volumes of sitting time. This study identified barriers and facilitators to breaking up sitting and reducing sitting time using the COM-B (Capability and Opportunity and Motivation) model, with Psychological Capability, Reflective Motivation, Automatic Motivation, Social Opportunity, and Physical Opportunity found to be predictors of workplace sitting behaviour. The Behaviour Change Wheel guide was followed, leading to the identification of 39 behaviour change techniques as active ingredients for intervention development. The final phase of the PhD was a pilot cluster-randomised controlled trial to test the efficacy of a multicomponent intervention including education, computer-prompt software and height-adjustable workstations, as well as managerial support. The intervention decreased sitting time and increased standing time in the workplace, with most participants meeting the two-hour minimum recommendation for standing up. The intervention also improved productivity but had no effect on cardiometabolic biomarkers or mental wellbeing outcomes. This study could serve as evidence for workplace managers on the benefits of such interventions and provides evidence to strengthen the need to tailor workplace interventions to employees’ needs to improve adherence.