[Translated article] Design and validation of IF-CSS frailty index based on the comprehensive geriatric assessment...

To validate the IF-CSS frailty index according to its predictive capacity for mortality and to define the intervals compatible with frailty states.

An observational, retrospective, multicenter study of a cohort of elderly patients from four nursing homes with a follow up between 12 and 38 months was conducted. The IF-CSS comprised 17 variables across four domains from the comprehensive geriatric assessment. Contrast of hypothesis log-rank for survival curves according to IF-CSS index was performed. The predictive model of survival time was performed using a parametric accelerated failure model.

535 patients with a mean age of 83.62 years (SD7.84) were included. Mortality rate during the study period was 39.8%. Survival curves by frailty intervals showed significant differences (χ² = 92; p < 0.001). The comparative analysis also showed significant differences for almost all the variables included in the construct. The parametric model of accelerated failure estimated a 29% reduction in survival time for each tenth of an increase in the IF-CSS.

The IF-CSS results in a tool with a frailty discriminative and mortality predictive capacity that allows its use in the care programs of nursing homes.