Kidney Week

Abstract: SA-PO1065

Convective Volume, Body Size, and Mortality in Hemodiafiltration: An Individual Patient Data Analysis of Randomized Trials

Session Information

• Kidney Replacement Therapy and Care Delivery Innovations
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Cromm, Krister, Fresenius Medical Care Deutschland GmbH, Bad Homburg, HE, Germany

Krister Cromm, MA, MS, MSc, MBA

• Vernooij, Robin W.m., Universiteit Utrecht, Utrecht, UT, Netherlands

Robin W.m. Vernooij, MS, MSc, PhD

• Hegbrant, Jorgen BA, Lunds Universitet, Lund, Skåne County, Sweden

Jorgen BA Hegbrant, MD, PhD

• Kotanko, Peter, Renal Research Institute, New York, New York, United States

Peter Kotanko, MD, FASN

• Woodward, Mark, The George Institute for Global Health UK, Oxford, England, United Kingdom

Mark Woodward, PhD

• Davenport, Andrew, University College London, London, England, United Kingdom

Andrew Davenport, MD

• Canaud, Bernard J., Universite Paul-Valery Montpellier 3, Montpellier, Occitanie, France

Bernard J. Canaud, MD, PhD

• Barth, Claudia Maria, B Braun Avitum AG, Melsungen, HE, Germany

Claudia Maria Barth, MD

• Rose, Matthias, Charite - Universitatsmedizin Berlin, Berlin, BE, Germany

Matthias Rose

• Blankestijn, Peter J., Universiteit Utrecht, Utrecht, UT, Netherlands

Peter J. Blankestijn, MD

• Bots, Michiel, Universiteit Utrecht, Utrecht, UT, Netherlands

Michiel Bots, MD, PhD

• Strippoli, Giovanni, Universita degli Studi di Bari Aldo Moro, Bari, Apulia, Italy

Giovanni Strippoli, MD, MS, MSc, PhD, MPH

Group or Team Name

• CONVINCE Scientific Committee and CONVINCE investigators

Background

Higher convective volumes in post-dilution online hemodiafiltration (HDF) are associated with improved survival, but whether this relationship differs according to body size remains uncertain. We evaluated the association of convective volume with body surface area (BSA) and body mass index (BMI) in randomized HDF trials.

Methods

We analyzed patients assigned to HDF in five European randomized trials included in a recent individual patient data meta-analysis comparing HDF with high-flux hemodialysis. Overall, 2083 patients treated with post-dilution online HDF were included. Associations between achieved convective volume and all-cause mortality were assessed using multivariable Cox proportional hazards models adjusted for demographic and clinical covariates. Effect modification by BSA and BMI was examined using interaction terms, and joint associations were explored using contour plots.

Results

Median delivered convective volume was 23.0 L/session (IQR 19.8–25.6). Patients in the highest convective volume tertile (>24.6 L/session) had lower mortality than those in the lowest tertile (<20.8 L/session) (adjusted hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.49–0.78). Each 1 L increase in convective volume was associated with a 4% lower mortality risk (HR 0.96, 95% CI 0.94–0.98; p<0.001). Contour plots showed lower mortality risk with higher convective volumes across a broad range of BSA and BMI values (Figure). However, neither BSA (p=0.17) nor BMI (p=0.67) significantly modified the association.

Conclusion

Higher achieved convective volume was associated with lower all-cause mortality independent of body size. These findings support fixed high-volume HDF targets rather than routine adjustment according to BSA or BMI.

Figure. Joint association of convective volume and body size with all-cause mortality in patients receiving post-dilution online hemodiafiltration (HDF).

Funding

• Government Support – Non-U.S.