Xuxi Zhang

poor balance, muscle weakness, shortness of breath and fear for falling. 13 Studies on the association between physical activity and frailty among older adults show contradictory results. Moreover, most of the longitudinal studies on physical activity and frailty examine baseline physical activity only in relation to changes in frailty 14, 15 , and studies on the association between change in physical activity and frailty are relatively limited. Therefore, we studied the longitudinal association between frequency of moderate physical activity and frailty as well as the association between a 12 ‐ month change in frequency of moderate physical activity and frailty in Chapter 3 (See Figure 9.1.1). Our results show that both maintaining a regular frequency of physical activity and increasing to a regular frequency of physical activity were associated with maintaining or improving the level of frailty among older adults, not only in the physical domain, but also in the psychological and social domains of frailty. In summary, the result support that maintaining a regular frequency of physical activity and (if not present) increasing to a regular frequency of physical activity could be a protective factor with regard to frailty. The third step of the public health framework is to determine how to prevent or control the problems. Frailty status might be reversible with the implementation of specific interventions. 16 ‐ 18 Therefore, to identify frail people has been proposed as a step for better management and control of frailty. 19 The Tilburg Frailty Indicator (TFI) is a short self ‐ reported questionnaire including 15 items addressing 3 domains: the physical, psychological and social domains. 20 However, research on the properties of the TFI is relatively limited. 21 For example, the TFI has not yet been validated in Greece, Croatia or the United Kingdom (UK). Evaluation of the TFI in several countries could help us to determine whether it works well in studying frailty in various populations (See Figure 9.1.1). In Chapter 4 , we assessed the reliability and validity of the full TFI and its three domains in a population of community ‐ dwelling older adults from 5 European countries, including Spain, Greece, Croatia, the Netherlands and the UK. In addition, the reliability and validity were assessed for each country separately. Our results support the reliability and validity of the TFI. So, the TFI may be applied as an instrument to measure frailty in community ‐ dwelling older adults for large ‐ scale population studies on frailty in the five European countries. For the third step of public health framework, it is also important to evaluate the process components of the interventions to increase the understanding of underlying reasons for why some works while another do not (See Figure 9.1.1). In Chapter 5 , we evaluated the process components of the implementation of the Urban Health Centres Europe (UHCE) approach using the Steckler and Linnan framework 22, 23 , including reach of the target population, dose of the intervention actually delivered to and received by participants, and satisfaction of main stakeholders with the intervention. The UHCE approach was a preventive coordinated care approach aimed at promoting healthy ageing by decreasing falls, polypharmacy, loneliness and frailty among community ‐ dwelling older adults. 24 The UHCE approach shows promising, but small positive effects in tackling recurrent falls and frailty; 25 the study shows that there may be barriers that hinder person’s engagement in care. Our results show that people in 9 223 General discussion