The Functional Continuum Scale in Relation to Hospitalization Density in Older Adults: The FRADEA Study

Background: There is a need to know the relationship between function and hospitalization risk in older adults. We aimed at investigating whether the Functional Continuum Scale (FCS), based on basic (BADL) and instrumental (IADL) activities of daily living and frailty, is associated with hospitalization density in older adults across 12 years of follow-up.

Methods: Cohort study, with a follow-up of 12 years. A total of 915 participants aged 70 years and older from the Frailty and Dependence in Albacete (FRADEA) study, a population-based study in Spain, were included. At baseline, the FCS, sociodemographic characteristics, comorbidity, number of medications, and place of residence were assessed. Associations with first hospitalization, number of hospitalizations, and 12-year density of hospitalizations were assessed using Kaplan-Meier curves, Poisson regression analyses, and density models.

Results: The median time until the first hospitalization was shorter toward the less functionally independent end of the FCS, from 3917 days (95% confidence interval [CI] 3701-3995) to 1056 days (95% CI 785-1645) (p < .001). The incidence rate ratio (IRR) for all hospitalizations increased from the robust category until the frail one (IRR 1.89), and thereafter it decreased until the worse functional category. Those who were BADL dependent presented an increased hospitalization density in the first 4 follow-up years (58%), those who were frail in the third-to-sixth follow-up years (55%), while in those prefrail or robust the hospitalization density was homogeneous during the complete follow-up.

Conclusions: The FCS is useful for stratifying the risk of hospitalization and for predicting the density of hospitalizations in older adults.