Could Frailty Explain Higher Mortality with Early Dialysis?

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A large majority of patients starting dialysis in the United States are in frail condition, which may be a factor in the increased mortality associated with dialysis initiation at higher estimated GFR (eGFR) levels, suggests a report in the Archives of Internal Medicine.

The study included 1576 patients initiating dialysis, identified through the Comprehensive Dialysis Study of the U.S. Renal Data System. On the basis of the presence of at least two of three criteria—slowness/weakness, exhaustion, and low physical activity—73 percent of patients were considered frail. Even among patients younger than 40, the rate of frailty at the start of dialysis was 63 percent.

On multivariate analysis, a higher estimated eGFR at the beginning of dialysis was independently associated with frailty (odds ratio 1.44 per 5 mL/min/1.73 m2). Frailty was also significantly associated with mortality (hazard ratio [HR] 1.57) and time to first hospitalization (HR 1.26).

Consistent with previous reports, higher eGFR at the start of dialysis was associated with increased mortality: HR 1.12 per 5 mL/min/1.73 m2. However, once the effects of frailty were accounted for, the association was no longer significant.

With the current trend toward earlier dialysis, lower eGFR when patients start dialysis has been linked to increased mortality. Frailty could be one factor affecting clinical decisions about starting dialysis. The new study finds that nearly three-fourths of patients meet the criteria for frailty at dialysis initiation.

Frailty is associated not only with higher eGFR at dialysis but also with a higher risk of death and hospitalization. The researchers call for further studies evaluating the effects of dialysis on overall health and functional status in frail patients. They add, “Comprehensive efforts other than dialysis aimed to improve functional capacity in this population should also be considered.” [Boa Y, et al. Frailty, dialysis initiation, and mortality in end-stage renal disease. Arch Intern Med 2012; 172:1071–1077].

September 2012 (Vol. 4, Number 9)