Longitudinal Analysis of Intrinsic Capacity and Other Risk Factors in Aging: FREVO Study Protocol.

Population aging presents important global and socio-economic challenges, especially in developing countries such as Brazil, where aging is projected to accelerate in the next years. This manuscript presents the protocol of the FREVO (risk factors in aging) study, a six-year longitudinal study that aims to assess intrinsic capacity and its interaction with other risk factors. Moreover, this study aims to evaluate the combination of these factors and their correlation with major adverse health outcomes among community-dwelling older adults in Petrolina, Brazil. This six-year prospective cohort study will recruit 496 participants aged 60 or older. Annual in-person assessments using validated tools will measure intrinsic capacity, personal information, lifestyle, and chronic conditions. Negative outcomes (falls, hospitalizations, dementia, and death) will be recorded biannually by phone. Statistical analyses will employ latent profile analysis to identify risk phenotypes and Cox regression models for time-to-event analyses. This study will attempt to identify phenotypes and modifiable risk factors by using the WHO's intrinsic capacity framework in a low-resource Brazilian context for the assessment and promotion of healthy aging. Our findings will address important gaps that can contribute to a localized understanding of aging, aligning global frameworks with regional realities to promote independence, functionality, and quality of life for older adults.