Abstract: Objective To evaluate the effect of high-efficiency on-line hemodiafiltration combined with hemodialysis on quality of life (QOL) and survival rate in maintenance hemodialysis (MHD) patients. Methods Eighty MHD patients were enrolled in this study. They were randomly divided into high-efficiency online hemodiafiltration combined with hemodialysis group (HDF+HD group, n=50) and hemodialysis group (HD group, n=30). Urea clearance index (Kt/V), phosphorus (Pi), HCO3
-, β2-microglobulin (β2-MG), C-reactive protein (CRP), serum albumin (ALB), subjective global nutritional assessment (SGA) and the MOS item short from health survey SF-36 (SF-36) were evaluated at the beginning, and at the 3rd, 6th, 12th, 36th and 60th months of the treatment. The five- year survival rate was calculated. Results At the beginning of the study, there were no significant differences in these related parameters between the two groups (P＞0.05). When comparison was performed between the two groups at the 12th, 36th and 60th month of the treatment, Kt/V, HCO3-, ALB, SGA and SF-36 were significantly increased in HDF+HD group (t=2.604 and P=0.011, t= 2.600 and P=0.011, t=2.598 and P=0.011 for Kt/V, respectively; t=7.693 and P＜0.001, t=12.917 and P＜
0.001, t=8.145 and P＜0.001 for HCO3- , respectively; t=6.618 and P＜0.001, t=7.688 and P＜0.001, t=7.519 and P＜0.001 for ALB, respectively; t=7.104 and P＜0.001, t=8.933 and P＜0.001, t=6.381 and P＜0.001 for SGA, respectively; t=17.366 and P＜0.001, t=13.971 and P＜0.001, t=11.748 and P＜0.001 for SF-36, respectively); Pi, β2-MG and CRP were significantly decreased in HDF+HD group (t=- 3.080 and P=0.003, t=-3.172 and P=0.002, t=-4.733 and P＜0.001 for Pi, respectively; t=-20.369 and P＜0.001, t=-21.205 and P＜0.001, t=-23.658 and P＜0.001 for β2-MG, respectively; t=-12.983 and P＜0.001, t=-19.689 and P＜0.001, t=- 17.395 and P＜0.001 for CRP, respectively.). In addition, Kaplan- Meier survival curve showed that the five- year survival rate was significantly higher in HDF+HD group than in HD group (χ2=3.917, P=0.048). Multivariate regression analysis demonstrated that SF-36 was negatively correlated with β2-MG (B＝-0.352, P＜0.001), and was positively correlated with SGA (β ＝0.772, P＜0.001). Conclusion Comparing with the conventional hemodialysis, high-efficiency on-line hemodiafiltration combined with hemodialysis can significantly enhance QOL and survival rate in MHD patients. The increased clearance of medium/large molecules toxins and better nutritional status may be the key factors for improved QOL.

Key words: End stage renal disease, Maintenance hemodialysis, High-efficiency on-line Hemodiafiltration, Quality of Life, Survival rate