Association of Performance-Based and Self–Reported Function–Based Definitions of Frailty with Mortality among Patients Receiving Hemodialysis

Abstract

Background and objectives Frailty is common among patients on dialysis and increases vulnerability to dependency and death.Design, setting, participants, & measurements We examined the predictive ability of frailty on the basis of physical performance and self-reported function in participants of a US Renal Data System special study that enrolled a convenience sample of 771 prevalent patients on hemodialysis from 14 facilities in the Atlanta and northern California areas from 2009 to 2011. Performance-based frailty was assessed using direct measures of grip strength (weakness) and gait speed along with weight loss, exhaustion, and low physical activity; poor selfreported function was substituted for weakness and slow gait speed in the self-reported function-based definition. For both definitions, patients meeting three or more criteria were considered frail.Results The mean age of 762 patients included in analyses was 57.1614.2 years old; 240 patients (31%) met the physical performance-based definition of frailty, and 396 (52%) met the self-reported function-based definition. There were 106 deaths during 1.7 (interquartile range, 1.4-2.4) years of follow-up. After adjusting for demographic and clinical characteristics, the hazard ratio (HR) for mortality for the performance-based definition (2.16; 95% confidence interval [95% CI], 1.41 to 3.29) was slightly higher than that of the self-reported function-based definition (HR, 1.93; 95% CI, 1.24 to 3.00). Patients who met the self-report-based definition but not the physical performance definition of frailty (n=192) were not at statistically significantly higher risk of mortality than those who were not frail by either definition (n=330; HR, 1.41; 95% CI, 0.81 to 2.45), but those who met both definitions of frailty (n=204) were at significantly higher risk (HR, 2.46; 95% CI, 1.51 to 4.01).Conclusions Frailty, defined using either direct tests of physical performance or self-reported physical function, was associated with higher mortality among patients receiving hemodialysis. Future studies are needed to determine the utility of assessing frailty in clinical practice.

Implications of Frailty for Peritransplant Outcomes in Kidney Transplant Recipients

“…Functional status may decline and fail to recover after a medical illness or intervention, placing the individual at higher risk for complications. Literature on frailty and kidney transplant outcomes use a wide range of definitions and myriad of metrics including: descriptive phenotype (Fried criteria 2 );descriptive scores (Frailty Index 3 , health-related quality of life [HRQOL] scores 4 );physical function testing (SPPB 5 , measures of lower extremity strength and grip strength 6 );cardiopulmonary exercise testing (peak VO 2 ) 7 , other functional tests (6-minute walk test, sit-to-stand, or timed walking tests 8 ;other surrogate measures (days of hospitalization 9 , falls 10 ).…”

Utility of Regular Management of Physical Activity and Physical Function in Hemodialysis Patients

“…These results suggest that it is important for hemodialysis patients to manage physical function and physical activity regularly as part of routine care to improve their prognosis. Chronic kidney disease is an independent risk factor for frailty, [8,[23][24][25][26][27][28] which is a predictor of injurious falls or fractures, [26] hospitalization, [8] and mortality [8,25,28]. Frailty among hemodialysis patients is primary characterized by physical inactivity and poor physical performance.…”

Dialysis in the Elderly and Impact of Institutionalization in the United States Renal Data System

“…Recent studies have shown that similar to how it is in the general population, frailty in predialysis and dialysis patients is associated with increased cognitive dysfunction and mortality [20,21]. …”