Determinant factors of functional status among the oldest old.

Background: The fastest-growing age group in Brazil and around the world is the oldest-old group (aged 80 and over). Among these individuals, the prevalence of disability and morbidity is higher than in other groups.

Objectives: To investigate the influence of socioeconomic, demographic, biological, health, nutritional, and social factors, as well as perceived health, on the functional status of the oldest old.