Author Affiliations: Department of Rehabilitation Medicine (Dr Kutner) and Department of Biostatistics and Bioinformatics (Ms Zhang), Emory University, Atlanta, Georgia.
In a national cohort of patients starting renal replacement therapy, Bao and colleagues1 classified 73% as frail using a modification of criteria proposed by Fried et al2 in their seminal delineation of a frailty phenotype. Bao et al1(p1071) describe frailty as “extremely common among patients starting dialysis in the United States” and, more generally, as a “clinical syndrome highly prevalent in the population with end-stage renal disease (ESRD).” While we fully support the recognition of frailty and understanding of contributors to frailty as valuable research objectives, the article by Bao et al1 provides a case in point that assignment of frailty classification is very dependent on the particular criteria and operational measures that are applied. In particular, reliance on a patient-reported measure of physical functioning (PF) as a substitute for performance-based measures of weakness and slowness specified in the frailty phenotype validated by Fried et al2 may yield a different picture of the prevalence of “frailty.”
Kutner NG, Zhang R. Frailty in Dialysis-Dependent Patients With End-Stage Renal Disease. JAMA Intern Med. 2013;173(1):78-79. doi:10.1001/2013.jamainternmed.750