Xuxi Zhang

INTRODUCTION Frailty is a multidimensional concept characterized by the loss of reserves including energy, physical ability, cognition and health. The prevalence of frailty strongly increases with age. 1 According to the 2018 Ageing Report of the European Commission, the percentage of European citizens aged 65 years or older will rise from 19% in 2018 to 29% in 2070. 2 This increase is predominantly caused by the percentage of citizens aged 80 years and older. 2, 3 Hence, it is anticipated that frailty will pose a larger public health problem in the near future. 3 ‐ 5 Maintaining a healthy lifestyle in older age is associated with a lower level of frailty. 3, 6 ‐ 8 However, studies on the association between physical activity (PA) and frailty among older adults show contradictory results. Some studies 4, 9 ‐ 11 suggest that regular PA may delay the onset of frailty and reduce its severity, but others 12 found that PA was not associated with a decreased risk for frailty among older adults. Second, most of the longitudinal studies on PA and frailty examine baseline PA only in relation to changes in frailty 11, 13 , and evidence on the association between change in PA and frailty is quite limited. Additionally, most studies 7, 11, 14, 15 on PA and frailty have been conducted in adults aged 50 to 70 years, and evidence on the longitudinal association between PA and frailty in adults older than 70 years is relatively scarce. Due to the multidimensional nature of frailty, it has been suggested that the physical, psychological and social dimensions of frailty should be considered. 16 However, most previous studies on PA and frailty have focused on physical frailty only 4, 9, 11 ‐ 13 , and to date there has been little research into psychological and social frailty. Therefore, the aim of our study was to examine the longitudinal association between frequency of moderate PA and overall, physical, psychological and social frailty among community ‐ dwelling older adults older than 70 years. Second, we assessed the association between a 12 ‐ month change in frequency of moderate PA and frailty. METHODS Participants This study is part of the Urban Health Centres Europe (UHCE) project which is aimed at promoting healthy ageing in older adults by means of integrated care pathways covering the adherence to medication, prevention of falls and frailty, and loneliness. 17, 18 Integrated care pathways were implemented in community settings at study sites in five European countries (Spain, Greece, Croatia, the Netherlands and the United Kingdom). At each study site, adults older than 70 years, who lived independently and were expected to be able to participate in the study for at least 6 months, were invited to participate. A total of 2325 participants were recruited between May 2015 and June 2017; 1215 were included in an integrated care pathway intervention; 1110 were enrolled in the control group. Participants in the 3 53 Longitudinal association between physical activity and frailty