The Impact of Hemodiafiltration Versus Hemodialysis on Uremic Symptoms, Physical Function: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

RATIONALE &

OBJECTIVE

Uremic symptoms and frailty in kidney failure may be driven by the accumulation of uremic toxins that are variably cleared by dialysis. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) that evaluated the effect of hemodiafiltration (HDF) compared to hemodialysis (HD) on uremic symptoms, physical function, and quality of life (QOL).

STUDY

DESIGN

Systematic review and meta-analysis.

SETTING & STUDY POPULATIONS: We searched Medline, EMBASE, Cochrane Library, CINAHL, and PROSPERO up to September 2024 for RCTs comparing maintenance HDF vs HD in adults with kidney failure.

SELECTION CRITERIA: RCTs with the following outcomes: uremic symptoms as measured by patient-reported outcome measures (PROMs), physical function, and QOL.

DATA EXTRACTION: Two reviewers independently screened abstracts and full texts, extracted data, and assessed risk of bias.

ANALYTICAL APPROACH: Random effects meta-analysis.

RESULTS

Of 1,226 identified articles, 117 were included for full-text review, of which 24 RCTs (16 parallel, 8 crossover) met inclusion criteria. Studies were mostly from Europe or Asia and recruited a total of 2,382 participants. HDF was primarily delivered for 4 hours, 3 times weekly, in post-dilution mode (15/24 studies). The prescribed effluent dose was reported in 14 of 24 studies and ranged from 15-24 L. Uremic symptoms including cramps, fatigue, gastrointestinal symptoms, headache, neuropathy, pain, itch, restless legs, and sleep disturbance were variably reported using general or disease-specific PROMs. In meta-analyses, HDF did not improve sleep, itch, pain, fatigue, or cramps compared with HD. Meta-analyses for physical function and QOL were not performed.

LIMITATIONS: RCTs were not representative of the general dialysis population, poor effluent dose reporting, lack of blinding, variability in PROMs and heterogeneity.

CONCLUSIONS

The evidence for HDF over HD for uremic symptoms and physical function remains limited due to the variability in HDF/HD prescriptions and PROMs used in clinical trials, risk of bias, and heterogeneity in treatment effects. Large, adequately powered, high-quality RCTs that use standardized, validated, reliable, and responsive PROMs are needed.

REGISTRATION: The protocol was registered on PROSPERO (CRD42022316562).