Parameters of hemodialysis adequacy and patients’ survival depending on treatment modalities

Introduction. Retrospective studies showed that hemodiafiltration was associated with a reduced risk of mortality compared with standard hemodialysis in the patients with end-stage renal disease. Recently, a few prospective randomized clinical trials found no advantage in survival with hemodiafiltration as compared with high-flux hemodialysis and low-flux hemodialysis. The aim of this study was to compare the parameters of hemodialysis adequacy and two-year survival of patients depending on the modality of hemodialysis. Material and Methods. A total of 159 hemodialysis patients were divided into 3 groups according to the type of hemodialysis treatment: group A - lowflux hemodialysis, group B - high-flux hemodialysis, and group C - hemodiafiltration. All patients had the same duration of hemodialysis sessions. The analysis included average one-year biochemical parameters, and two-year survival of patients. Results. The patients on hemodiafiltration were significantly younger, they had longer dialysis vintage and higher index of dialysis adequancy as compared with the patients on low-flux hemodialysis and high-flux hemodialysis, but without a difference between the two latter groups. Compared to the patients on low-flux hemodialysis, the patients on hemodiafiltration and high-flux hemodialysis had significantly higher hemoglobin value with less frequent erythropoietin stimulating agent use. According to Kaplan-Meier survival analysis, the patients on hemodiafiltration and high-flux hemodialysis had significantly better two-year survival than the patients on low-flux hemodialysis. Cox proportional hazards model confirmed that high-flux hemodialysis caused a significantly lower relative risk of mortality (56% reduction) compared to low-flux hemodialysis (hazard ratio 0.44; P=0.026), and hemodiafiltration caused a 58% reduction in the relative risk of mortality compared to low-flux dialysis (hazard ratio 0.42; P=0.105), but without a statistical significance. Conclusion. This study has demonstrated two-year survival benefit with high-flux hemodialysis and hemodiafiltration compared with low-flux hemodialysis. There was no difference in survival between high-flux hemodialysis and hemodiafiltration groups.