Reproducibility and validity of the Portuguese Edmonton Frail Scale version in cardiac surgery patients

Frailty is a multidimensional syndrome characterized by the loss of functional reserve, associated with higher mortality and less functional survival in cardiac surgery patients. The Edmonton Frail Scale (EFS) is a comprehensive tool devised for brief frailty detection. To the best of our knowledge, there are no culturally adapted and validated frailty screening tools that enable the identification of vulnerability domains suited for use in the preoperative setting in Portugal. This was the motivation for this study.

To assess the validity and reproducibility of the Portuguese version of the EFS.

Prospective observational study, in a sample of elective cardiac surgery patients. The Edmonton Frail Scale (EFS) translation and backtranslation were performed. Demographic and clinical data were collected, and the translated EFS translated, Geriatric Depression Scale, and Mini Mental State Examination Portuguese versions, Katz and Clinical Frailty Scales were administered. To assess validity Mann-Whitney test, Spearman's correlation coefficient, marginal homogeneity test and Kappa coefficient were employed. Reproducibility was assessed estimating kappa coefficient for the frailty diagnosis and the 11 EFS items. Intra-class correlation coefficients and the corresponding 95% confidence interval were estimated using linear mixed effects model.

The EFS Portuguese version revealed construct validity for frailty identification, as well as criterion validity for cognition and mood domains. Reproducibility was demonstrated, with k=0.62 (95% confidence interval (CI) 0.42-0.82) and intraclass correlation (ICC)=0.94 (95% CI 0.89-0.97) in inter-observer test and k=0.48 (95% CI 0.26-0.70) and ICC=0.85 (95% CI 0.72-0.92) in intra-observer test.

The EFS Portuguese version is valid and reproducible for use, suiting pre-operative frailty screening in a cardiac surgery setting.