Comparison of Two Models of Frailty for the Prediction of Mortality in Brazilian Community-Dwelling Older Adults: The FIBRA Study.

Abstract

Prevalence of frailty is significant in Latin America. However, no previous study evaluated mortality prediction using the two most used frailty models in Brazil. The aim of the present study was to compare the frailty phenotype and the frailty index with regard to accuracy in the prediction of mortality among community-dwelling older adults. A cohort study was conducted involving 674 older adults. Thirty-five variables (signs, symptoms, chronic diseases and disabilities) were used for the construction of the frailty index (FI). The frailty phenotype index (FPI) was defined based on the criteria proposed in the Cardiovascular Health Study. Periodic verifications were performed in the databank of the Mortality Information System. Cox regression was used to estimate the relative risk (RR) of mortality and Kaplan-Meier survival curves were used in the analysis. The prevalence of frailty was greater based using the FI (16.3%) compared to the FPI (5.34%). Older adults classified as frail by the FPI had a greater risk of death (RR: 10.03; 95% CI: 4.43-22.74) that those classified as frail by the FI (RR: 0.87; 95% CI: 0.25-3.00). The lowest survival rate was found in the group of older adults classified as frail based on the FPI and classified as pre-frail and robust based on the FI. The FPI demonstrated greater accuracy in predicting the risk of mortality among Brazilian older adults than the FI. The validation of frailty measures is fundamental to the identification of older adults who are more vulnerable to adverse health events.