Detailed Description:

Investigational device: The eforto® system was developed based on approximatively 20 years of scientific research on handgrip muscle fatigability performed by the Frailty in Ageing research department (see https://fria.research.vub.be/) and in collaboration with top-level international partners. The eforto® system allows self-assessment of muscle fatigability and self-perceived fatigue in older adults and functions as a monitoring tool for intrinsic capacity. It is a small device, easy to use, and suitable for home measurements as well as hospital settings. When used correctly, the measurements cause no discomfort and can be performed repeatedly. The rubber bulb connects to a smartphone application that provides verbal test instructions to the participant. The app will guide the participant during the test and automatically provide motivational cues via audio. The test results are aggregated and stored in a cloud platform where the researcher can manage subjects, access the test data and export it for further analysis. The mobile app supports Dutch, French and English. In a previous study, eforto® was clinically validated against a gold-standard pressure gauge in n=61 community-dwelling older adults, n=26 hospitalized geriatric patients and n=25 older hip fracture patients. Moreover, the usability and acceptance of eforto® self-monitoring (1 week) was demonstrated in a sample of n=30 community dwelling older persons aged between 83 and 95 years old. (paper submitted for publication in international peer-reviewed journal) Procedures: After the recruitment, a researcher will estimate whether the participant is eligible for the study during a eligibility check by a telephone call and legally capable to provide consent. After informed consent is given, baseline measurements will take place. These measurements will be reassessed after 6 months and 12 months. After an individual information session explaining how to use eforto®, the participant will be instructed to perform the eforto® measurements for 2 consecutive days per week for 12 months at home (if needed with assistance by an informal caregiver). Preferentially, the researcher will install the eforto® application on the smartphone of the participant. The home measurements will be continued for 12 months or until withdrawal of the participant. During the study, there will be a monthly telephone contact between participants and researchers in order to register technical problems, and self-reported changes in health situation.}}