Comparison of Self-report − Based and Physical Performance − Based Frailty Definitions Among Patients Receiving Maintenance Hemodialysis

• Published in: American journal of kidney diseases Vol. 64; no. 4; pp. 600 - 607
• Main Authors: Johansen, Kirsten L., MD, Dalrymple, Lorien S., MD, MPH, Delgado, Cynthia, MD, Kaysen, George A., MD, PhD, Kornak, John, PhD, Grimes, Barbara, PhD, Chertow, Glenn M., MD, MPH
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-10-2014; Elsevier
• Subjects: Activities of Daily Living; Adult; Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Asthenia - diagnosis; Asthenia - epidemiology; Asthenia - etiology; Biological and medical sciences; Body Composition; Cross-Sectional Studies; Emergency and intensive care: renal failure. Dialysis management; end-stage renal disease (ESRD); Female; Frailty; hemodialysis; Humans; Intensive care medicine; Kidney Failure, Chronic - blood; Kidney Failure, Chronic - physiopathology; Kidney Failure, Chronic - psychology; Kidney Failure, Chronic - therapy; Male; Medical sciences; Middle Aged; Nephrology; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; physical activity; Physical Endurance; Physical Fitness; physical function; physical performance; Predictive Value of Tests; Prevalence; Renal Dialysis - adverse effects; Renal Dialysis - methods; Renal failure; Self Report; self-reported function; Sensitivity and Specificity; Sickness Impact Profile; United States - epidemiology; Weight Loss; United States; self-reported function; end-stage renal disease (ESRD); hemodialysis; Frailty; physical performance; physical function; physical activity; Kidney disease; Physical exercise; Human; Nephrology; Urinary system disease; Chronic renal failure; Physical performance; Self evaluation; Hemodialysis; Definition; Terminal stage; Urology; Extrarenal dialysis; Renal failure; Comparative study
• ISSN: 0272-6386; 1523-6838
• DOI: 10.1053/j.ajkd.2014.03.016

Background A well-accepted definition of frailty includes measurements of physical performance, which may limit its clinical utility. Study Design In a cross-sectional study, we compared prevalence and patient characteristics based on a frailty definition that uses self-reported function to the classic performance-based definition and developed a modified self-report−based definition. Setting & Participants Prevalent adult patients receiving hemodialysis in 14 centers around San Francisco and Atlanta in 2009-2011. Index Tests Self-report−based frailty definition in which a score lower than 75 on the Physical Function scale of the 36-Item Short Form Health Survey (SF-36) was substituted for gait speed and grip strength in the classic definition; modified self-report definition with optimized Physical Function score cutoff points derived in a development (one-half) cohort and validated in the other half. Reference Test Performance-based frailty defined as 3 of the following: weight loss, weakness, exhaustion, low physical activity, and slow gait speed. Results 387 (53%) patients were frail based on self-reported function, of whom 209 (29% of the cohort) met the performance-based definition. Only 23 (3%) met the performance-based definition of frailty only. The self-report definition had 90% sensitivity, 64% specificity, 54% positive predictive value, 93% negative predictive value, and 72.5% overall accuracy. Intracellular water per kilogram of body weight and serum albumin, prealbumin, and creatinine levels were highest among nonfrail individuals, intermediate among those who were frail by self-report, and lowest among those who also were frail by performance. Age, percentage of body fat, and C-reactive protein level followed an opposite pattern. The modified self-report definition had better accuracy (84%; 95% CI, 79%-89%) and superior specificity (88%) and positive predictive value (67%). Limitations Our study did not address prediction of outcomes. Conclusions Patients who meet the self-report–based but not the performance-based definition of frailty may represent an intermediate phenotype. A modified self-report definition can improve the accuracy of a questionnaire-based method of defining frailty.