Clinical Outcomes and Consumption in Extended Hemodialysis and Online Hemodiafiltration: Multicenter Analysis

Background: Extended hemodialysis (HDx) combines diffusive and convective transport using cut-off membranes. Considering its potential as an alternative to online hemodiafiltration (OL-HDF), we conducted a comparative study between the two techniques. Methods: A retrospective analysis in 10 outpatient dialysis centers during 2024. Patients on HDx or OL-HDF for at least 360 days, with 90 recorded treatments, were included. Patients on incremental or palliative hemodialysis were excluded. Demographic, clinical, and laboratory variables (at baseline, 6 and 12 months), emergency hospitalizations, and annual consumption of dialysis medications (sodium heparin, erythropoiesis-stimulating agents [ESA], iron, paricalcitol, etecalcetide) were collected. The comparative analysis used Propensity Score Matching (PSM) and Inverse Probability of Treatment Weighting (IPTW) with Doubly Robust Estimation, using R (v4.4.3). The final cohort included 40 patients on HDx and 253 on OL-HDF. Results: After adjusting for age, gender, time on dialysis, diabetes, hypertension, vascular access, Charlson and Karnofsky indices, frequency and duration of sessions, and average annual blood flow (Qb), statistically significant differences were found: hemoglobin levels and transferrin saturation index (TSI) were higher in HDx, and serum potassium was lower. No differences were observed in albumin, β2-microglobulin, or the risk of urgent hospitalization. Regarding medication use, HDx showed significantly lower use of iron sucrose and etecalcetide and higher use of sodium heparin. The trend toward lower use of AEE and paricalcitol in HDx did not reach statistical significance Conclusion: Although differences in hemoglobin, IST, and potassium were identified, these are not considered clinically relevant. In our experience, HDx and HDF-OL showed comparable efficacy in median solute clearance and analytical parameters with no differences in urgent hospitalization events. HDx may offer additional advantages, such as reduced consumption of certain drugs and potential water savings compared to HDF-OL.