Comparison of survival between dialysis patients with incident high-flux hemodialysis versus on-line hemodiafiltration: A single center experience in Saudi Arabia

Conventional hemodialysis (HD) is the most common treatment modality used for renal replacement therapy. The concept of HD is based on the diffusion of solutes across a semipermeable membrane. Hemofiltration (HF) is based on convective transport of solutes; hemodiafiltration (HDF) is based on combined convective and diffusive therapies. Data about survival benefit of on-line HDF (OL-HDF) over high-flux HD (HF-HD) is conflicting. We conducted this study to investigate if there is a survival difference between the two treatment modalities. This study is a retrospective, single-center study in which 78 patients were screened; 18 were excluded and 60 patients were analyzed. The study patients were aged 47.5 ± 20.7 years, 33 patients (55%) were on HF-HD, and 27 patients (45%) were on OL-HDF. A total of 24 patients (40%) of both groups were diabetic and, the mean duration on dialysis was 43.5 ±21.3 months in the HF-HD group and 41.2 ± 22.0 months in the OL-HDF group. The mean substitution volume for OL-HDF was 22.3 ± 2.5 L. Survival was 73% [95%, confidence interval (CI) 60-84] in the HF-HD group and 65% (95%, CI 54-75) in the OL-HDF group by the end of the study period. The unadjusted hazard ratio (HR) with 95% CI comparing HF-HD to high-volume postdilution OL-HDF was 0.78 (0.10-5.6; P = 0.810). Kaplan-Meier analysis for patient survival over five years showed no significant difference between the two modalities. Prospective controlled trials with a larger number of patients will be needed to assess the long-term clinical outcome of postdilution OL-HDF over HF-HD.