- physically frail (pre-frail or frail, based on the criteria designed by Fried et al.) (30). Frailty will be defined as a clinical syndrome in which one or more of the following criteria are present: unintentional weight loss (4.5 kg in past year), self-reported exhaustion (CES-D questionnaire), weakness (grip strength), slow walking speed and low physical activity (Minnesota questionnaire). More details on these criteria are described in chapter 6.3.2.