Investigating digital behaviour change interventions for physical activity and sedentary behaviour in socially isolated older adults

Many older adults, especially those who are socially isolated, are insufficiently physically active and spend prolonged periods of time engaging in sedentary behaviours. Social isolation, insufficient physical activity (PA) and increased sedentary behaviour (SB) are independently associated with negative health outcomes. Traditional PA/SB interventions have achieved limited success, particularly in the long term, therefore novel interventions are required. This thesis followed the Medical Research Council (MRC) guidance on complex intervention development and used the Behaviour Change Wheel (BCW) to make recommendations for a digital behaviour change intervention (DBCI) for PA/SB in socially isolated older adults. This included undertaking four studies that addressed the three stages of the development phase of the MRC guidance. First, a systematic review and meta-analysis (n = 22 studies) found DBCI were effective in increasing total PA and moderate-to-vigorous PA by 52min/week, and reduced SB by 58min/day in older adults (≥ 50 years). A minimum of three behaviour change technique (BCT) clusters were found to increase efficacy of the DBCI, including social support, goal setting, feedback on behaviour and self-monitoring. Second, an analysis of data from the English Longitudinal Study of Ageing, found over two thirds of socially isolated older adults used the internet/email at least once a week and were more likely to access it via a laptop than any other device. Non-linear relationships were found between frequency of use and social isolation. Third, semi-structured interviews highlighted that socially isolated older adults preferred individual/small-group PA that they could undertake either at home or from their home, and their physical capabilities prevented them from engaging in certain types of PA. Fourth, socially isolated older adults’ experiences of using two commercially available DBCI for PA/SB, and their ideas for future DBCI for PA/SB, were explored via semi-structured interviews. Generally, participants enjoyed using the DBCI and found it useful for increasing their PA, but they require a DBCI that is better tailored to their needs. The aim of this thesis was to use the MRC guidance on developing and evaluating complex interventions, in combination with the BCW, to make recommendations for the design of a DBCI for PA and/or SB in socially isolated older adults.