Research Article
Itziar Vergara, Mónica Mach
Abstract
Background: Frailty is one of the most relevant clinical expressions of ageing and a powerful indicator of the health status of older populations. Tools to identify frailty can be classified into three groups based on rules (the Tilburg Frailty Indicator (TFI)), functional performance (Gait Speed (GS) and Timed Up and Go (TUG) tests), and biomarkers (e.g., SOX2 expression). This study explores the concordance between two functional tests (GS and TUG), blood SOX2 levels and TFI scores in assessing frailty. Method and analysis: The proposed research is a nested case-control study of community-dwelling adults, aged 75 years or older, from a prospective cohort study with two years of follow-up (the KoS-frail study). All surviving individuals from the original cohort will be invited to participate and will receive a comprehensive assessment including questionnaires, functional performance and blood tests. Then, a nested case control will be set up considering frail or robust status as measured by TFI. TFI scores ≤5 will be considered cases. Assessment will consist of a personal interview and blood (SOX2 levels) and physical performance tests (GS and TUG). Additionally, TIF will be translated into Spanish, cross-culturally adapted and validated. Conclusions: There is a need for an effective tool that can easily identify frail individuals in primary care at an early stage of decline. This study seeks to assess the concordance between existing tools for identifying frail individuals. This work will also provide a validated Spanish version of the TIF.