Interventions for promoting physical activity and reducing sedentary time among people aged 55 years and older: an overview of systematic reviews

BACKGROUND: Physical inactivity and prolonged sedentary behaviours are common among older adults, leading to an increased risk of chronic diseases and mortality. We aimed to synthesise existing systematic reviews of interventions for promoting physical activity and reducing sedentary time among people aged 55 years and older. METHODS: We searched five electronic databases (PubMed, CINAHL, Scopus, Cochrane and SportDiscus) and identified systematic reviews of randomised controlled trials on interventions to promote physical activity and reduce sedentary behaviours among adults aged 55 years or older. The methodological quality of each systematic review was assessed using the AMSTAR-2 tool. A narrative synthesis was used to group findings of the included reviews by type of interventions (e.g. technology-based intervention, exercise and behavioural intervention) and outcome measure [e.g. total physical activity, step counts, moderate to vigorous physical activity (MVPA) and sedentary time]. Meta-analyses of the original studies were conducted to explore the effect of different types of intervention on the outcomes in the short and intermediate term. RESULTS: A total of 21 systematic reviews were included, 17 of which conducted meta-analyses. Seven reviews were of moderate quality, 11 were of low quality and three were of critically low quality. For six meta-analysis of exercise and behavioural interventions, two reported a significant difference in physical activity after 12 months, two found no significant difference and two presented mixed findings across subgroups. Only one meta-analysis reported an effect on sedentary time and observed no significant improvement. For technology-based interventions, six of seven meta-analyses demonstrated significant increases in physical activity. All five meta-analyses reported significant improvements in step counts, and four of five meta-analyses showed significant benefits for MVPA. Two meta-analyses reported inconsistent findings on sedentary time. The above results were partially supported by our meta-analysis results. CONCLUSION: Consistent evidence suggests that technology-based interventions are effective in increasing physical activity, step counts and MVPA, whereas inconsistent findings support the effectiveness of exercise and behavioural interventions in increasing physical activity. Limited evidence examines interventions to reduce sedentary time, and future research targeting sedentary behaviours is needed.