Physical activity in community-dwelling older people: a review of systematic reviews of interventions and context

Abstract Background Research evidence on the importance of physical activity for prevention and delay of long-term conditions is strong. However, activity rates decline substantially over the life course, particularly around later life. This review is part of a comprehensive evidence synthesis of preventive interventions in older age, with a focus on healthy behaviours to identify evidence gaps and inform policy relating to ageing well and cognitive health. An overview of systematic reviews of physical activity was conducted to explore in adults aged 55 years and older: (review 1) the effectiveness of physical activity for primary prevention of cognitive decline and dementia; (review 2) interventions effective for increasing physical activity uptake and maintenance; and (review 3) barriers and facilitators to physical activity. Methods Multiple databases were searched for studies in English from Organisation for Economic Co-operation and Development countries between 2000 and 2014 (Medline, Embase, PsycINFO, CINAHL, Social Science Index, the Cochrane Collaboration and Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and York CRD Database). Search strategy covered the following domains and concepts: ageing and older people; health behaviours and risk reduction relating to diet, physical activity, inactivity, alcohol, smoking; and risk reduction relating to loneliness and isolation, sun exposure, hearing, and vision. The quality of reviews 1 and 2 were assessed with AMSTAR. Findings 35 systematic reviews were included. In review 1 (12 systematic reviews, 7751 participants), physical activity conferred mild, positive effects on cognition in older adults with and without previous cognitive impairment. However, evidence of a dose–response association was insufficient, and evidence on the effects of physical activity on delay of cognitive decline and dementia onset was inconclusive. The evidence in review 2 (16, 75 194) supported the effectiveness of various interventions, including group-delivered, centre-based, and cognitive approaches on short-term uptake of physical activity behaviour. In review 3 (7, 15 921), barriers included health status, previous physical activity habits and experiences, and cultural sensitivity, whereas facilitators included enjoyable activities and convenient scheduling. Interpretation Physical activity can offer small benefits to brain health, but evidence on how much activity