Despite the beneficial effects of middle-molecule removal by
high-flux dialysis, the effects of dialyzer membrane flux on
mortality are controversial. A number of observational studies
have suggested that HD using high-flux dialysis membrane results
in improved outcomes compared with low-flux dialysis [4–7].
However, two large randomized clinical trials, the HEMO study
and the European Membrane Permeability Outcome (MPO)
study, showed no significant survival difference between HD using
high-flux dialysis membrane and HD using low-flux dialysis
membrane [8,9]. This discrepancy may be due to differences in
the populations studied or study design.