Validity of an iPhone App to Detect Frailty and Sarcopenia Syndromes in Community Dwelling Older Adults: Protocol for a Diagnostic Accuracy Study

Frailty and sarcopenia are two age-related syndromes which can result in adverse health-related events. The combination of both is more predictive of mortality than either condition alone. These conditions can be reversed through an early detection and appropriate interventions. Nevertheless, scientific community highlights the lack of cheap, portable, rapid and easy-to-use tools for detecting frailty and sarcopenia in combination. The aim of this study is to validate an iPhone App to detect frailty and sarcopenia syndromes in community dwelling older adults. This is a protocol study of a retrospective diagnostic test accuracy study which will include at least 400 participants older than 60 years recruited from elderly social centers of Murcia city. Researchers will recollect data of health status, dependency, cognitive status, and functional capacity of the participants. The index test will consist in the measurement of muscle power exerted during a single Sit-to-stand through an App (iPhone), combined with calf and mid-upper arm circumference. The reference standard will be frailty syndrome and sarcopenia assessed according to Fried's phenotype and to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) (2019) recommendations, respectively. Sensitivity, specificity, positive predictive value, negative predictive values, and area under the curve will be reported.