Combined Contribution of Reduced Functional Mobility, Muscle Weakness, and Low Serum Albumin in Prediction of All-Cause Mortality in Hemodialysis Patients: A Retrospective Cohort Study

Objectives: The combined effects of reduced functional mobility, muscle weakness, and low serum albumin on mortality in hemodialysis patients have not been clarified. Here, we examined the associations of reduced functional mobility, muscle weakness, and low serum albumin-both alone and in combination-with all-cause mortality in hemodialysis patients. Methods: A total of 490 patients treated between July 2010 and October 2016 were enrolled retrospectively in this study. The independent prognostic effect of the combination of reduced functional mobility, muscle weakness, and low serum albumin on survival was estimated by Cox proportional hazard regression analysis. We calculated the increases in predictive capacity by combining the associations of reduced functional mobility, muscle weakness, and low serum albumin in comparison to each component alone based on the receiver-operating characteristic curves, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results: The final study population consisted of 314 hemodialysis patients, and 56 patients died during the 6.5-year follow-up period. The high Combined score group showed a significantly lower cumulative survival rate than the low Combined score group (hazard ratio, 3.30; 95% confidence interval, 1.59-6.87; P = .001). Both NRI and IDI suggested that the addition of Combined score to patient characteristics improved discrimination of patients at high risk of mortality (NRI, 0.038 95% CI: 0.096 - 0.064, P < .001 IDI, 0.029 95% CI: 0.004 - 0.055, P = .025). Conclusions: The combined assessment of reduced functional mobility, muscle weakness, and low serum albumin was associated with poorer prognosis in patients on hemodialysis. The results presented here indicated that the combination of reduced functional mobility, muscle weakness, and low serum albumin is useful for accurate prediction of prognosis in hemodialysis patients. (C) 2018 by the National Kidney Foundation, Inc. All rights reserved.