Abstract: Objective To investigate the symptoms occurred in patients receiving hemodiafiltration (HDF), and to analyze the relationship between the symptoms and HDF dose.  Methods  This was a cross-sectional study. Patients receiving regular maintenance hemodialysis thrice a week as well as post-diluted HDF at least once a week between November 2024 and January 2025 were recruited. Patients’ general data, HDF information and laboratory examinations were collected. Symptom burden was assessed using the Dialysis Symptom Index (DSI). The relationship between symptom burden and HDF dose was analyzed.  Result  A total of 179 patients were included in this study. The total DSI was 12.00 (9.00, 17.00) points. The first 5 most common symptoms were dry skin (89.94%), itching (81.56%), dry mouth (81.01%), feeling irritable (76.53%) and fatigue (68.72%). The first 5 most severe symptoms were irritable feeling [2.00 (1.00, 2.00) points], difficult falling asleep [1.00 (0.00, 2.00) points], dry skin [1.00 (1.00, 2.00) points], itching [1.00 (1.00, 2.00) points], and dry mouth [1.00 (1.00, 2.00) points]. The weekly convective volume of HDF was 41.44 (35.01, 53.76) L. With the increase of HDF frequency, weekly convective volume and β2-microglobulin reduction rate increased (H=122.516 and 24.138, P<0.001), accompanied by the decrease of pre-treatment β2-microglobulin levels (H=20.903, P<0.001). Patients receiving HDF therapy twice weekly(Z=-2.388，P=0.017) or thrice weekly (Z=-2.182, P=0.029) demonstrated lower total DSI scores compared to those receiving therapy once weekly. Locally weighted regression analysis showed that when convection volume is over 51.94 L/week, patients' DSI showed a downward trend.  Conclusion  Patients receiving HDF often experience a considerable symptom burden. The symptom burden can be improved with the increase of HDF dose, which is probably attributed to the clearance of medium molecular toxins. Higher HDF dose may improve patient’s symptom experience and long-term outcomes.

Key words: Hemodiafiltration, Symptom burden, Dialysis dose, Patient reported outcome