Author(s): MAIR, J., AGUIAR, E.J., BUCHAN, D., SCULTHORPE, N., Institution: SINGAPORE-ETH CENTRE, Country: SINGAPORE, Abstract-ID: 1825

INTRODUCTION:
Nationwide lockdowns in 2020 due to the coronavirus pandemic severely limited opportunities to engage in physical activity (PA). Worldwide step count data has since shown that, on average, PA declined by 27% in the first 30 days since declaration of the pandemic [1]. Older adults were among those considered more vulnerable than others and were asked to stay home for longer. Just-in-time-adaptive-interventions (JITAIs) can be delivered remotely via smartphones, at scale, providing real-time ‘in the moment’ behaviour change support to people when they need it most. This study describes the efficacy of a personalised JITAI on PA in older adults during the COVID-19 pandemic.
METHODS:
The JitaBug mHealth app delivered just-in-time PA promotion messages that were adapted using real-time PA (from Fitbit Charge 4), location, and weather data to encourage achievement of personalised PA goals. We tested the preliminary efficacy of JitaBug with older adults in a 6-week quasi-experimental study between October – December 2020. The intervention was delivered entirely remotely. Physical activity was measured using an Actigraph wrist-worn accelerometer during a baseline and follow-up period and using intra-day Fitbit data throughout the intervention. Actigraph data were processed using the GGIR package v2.1.0 and synchronised Fitbit data were analysed using the stepmetrics package v0.1.2 using R. Metrics of interest were time spent inactive and in low, and moderate-vigorous intensity PA, daily step count, and peak step cadence (as a proxy of intensity). Differences in PA between baseline and post-intervention were analysed using a paired-samples t-test.
RESULTS:
Thirty-one older adults (mean ± SD; 65.5 ± 5.4 years) completed the intervention. Valid Actigraph and Fitbit data were obtained from n=27 and n=24 participants, respectively. There was no significant change in Actigraph-measured time spent inactive (mean difference; 10.2 mins; p=0.936), light intensity PA (-9.31 mins; p=0.98), or moderate-vigorous PA (-4.02 mins; p=0.835) due to the intervention. At baseline, average daily step count was 8581 ± 3559 steps/day, while peak30 and peak60 cadences were 86 ± 22 steps/min and 73 ± 22 steps/min, respectively, indicating overall low intensity PA.
CONCLUSION:
The findings revealed that the JitaBug mHealth intervention supported older adults to maintain PA during the COVID-19 pandemic despite significant disruption to PA opportunities. JITAIs are a promising way to promote PA remotely to older adults in everyday life and may be used to reach those who may otherwise have limited access to PA support.

[1] GH Tison, R Avram, P Kuhar, et al. Worldwide Effect of COVID-19 on Physical Activity: A Descriptive Study. Ann Intern Med.2020;173:767-770.