Effects of hemodialysis dose and membrane flux on health-related quality of life in the HEMO Study.

BACKGROUND: It has been widely supposed that high dose and high flux hemodialysis would affect the quality as well as the length of life of patients treated by maintenance hemodialysis. The HEMO Study examined changes in health-related quality of life as a secondary study outcome. Specific hypotheses were that study interventions would affect physical functioning, vitality, Short Form-36 Health Survey (SF-36) physical and mental component summary scores, symptoms and problems associated with kidney disease, and sleep quality. METHODS: At baseline and annually, subjects responded to both the Index of Well-Being and the Kidney Disease Quality of Life-Long Form questionnaires. The interventions were assessed on the basis of their average effects over 3 years. RESULTS: At baseline, the SF-36 physical component summary score was lower than in healthy populations, but the mental component score was nearly normal. Over 3-year follow-up, physical health continued to decline; mental health and kidney disease-targeted scores remained relatively stable. The high dose hemodialysis intervention was associated with significantly less pain (4.49 points, P < 0.001) and higher physical component scores (1.23 points P= 0.007), but these effects were small compared to the natural variability in scores. High flux membranes were not associated with statistically significant differences in health-related quality of life. CONCLUSION: The HEMO Study results demonstrate the marked burden of chronic kidney failure and hemodialysis treatment on daily life. In this trial among patients undergoing maintenance three times a week hemodialysis, the SF-36 physical component summary score and pain scale showed significant but very small clinical effects favoring the higher dialysis dose. No clinically meaningful benefits or either the dose or flux interventions were observed for other indices of health-related quality of life.

Effect of dialysis dose and membrane flux in maintenance hemodialysis.

BACKGROUND: The effects of the dose of dialysis and the level of flux of the dialyzer membrane on mortality and morbidity among patients undergoing maintenance hemodialysis are uncertain. METHODS: We undertook a randomized clinical trial in 1846 patients undergoing thrice-weekly dialysis, using a two-by-two factorial design to assign patients randomly to a standard or high dose of dialysis and to a low-flux or high-flux dialyzer. RESULTS: In the standard-dose group, the mean (+/-SD) urea-reduction ratio was 66.3+/-2.5 percent, the single-pool Kt/V was 1.32+/-0.09, and the equilibrated Kt/V was 1.16+/-0.08; in the high-dose group, the values were 75.2+/-2.5 percent, 1.71+/-0.11, and 1.53+/-0.09, respectively. Flux, estimated on the basis of beta2-microglobulin clearance, was 3+/-7 ml per minute in the low-flux group and 34+/-11 ml per minute in the high-flux group. The primary outcome, death from any cause, was not significantly influenced by the dose or flux assignment: the relative risk of death in the high-dose group as compared with the standard-dose group was 0.96 (95 percent confidence interval, 0.84 to 1.10; P=0.53), and the relative risk of death in the high-flux group as compared with the low-flux group was 0.92 (95 percent confidence interval, 0.81 to 1.05; P=0.23). The main secondary outcomes (first hospitalization for cardiac causes or death from any cause, first hospitalization for infection or death from any cause, first 15 percent decrease in the serum albumin level or death from any cause, and all hospitalizations not related to vascular access) also did not differ significantly between either the dose groups or the flux groups. Possible benefits of the dose or flux interventions were suggested in two of seven prespecified subgroups of patients. CONCLUSIONS: Patients undergoing hemodialysis thrice weekly appear to have no major benefit from a higher dialysis dose than that recommended by current U.S. guidelines or from the use of a high-flux membrane.