Average Acute (first six months) and Chronic Slopes (> 6 months) of Predialysis β2M Concentration according to Reuse Quartile and Membrane Flux.

Estimates of slopes are given in Δmg/L β2M/year relative to the first quartile of reuse in each flux arm (entry in rows labelled “0–6”); all estimates were obtained by a joint model for the (untransformed) β2M concentration and survival. The longitudinal and survival submodels adjusted for reuse quartile, flux and Kt/V assignments, age, sex, diabetes, duration of ESRD dependency (upon study enrolment), ICED, albumin, vascular access, pre-randomization flux, residual urine volume, study center and the interaction between reuse quartile by flux. To model the changing trajectories of β2M as a result of patients being assigned to dialyzers with a different flux than the one used before randomization, the longitudinal component also included interactions between pre- and post-randomization flux and a spline function of time since randomization. The baseline hazard of the survival submodel was modeled with a natural spline with two internal knots at 45 and 90 days and two boundary (external) knots at 0 and 180 days.ǂP-values comparing each slope to the reference category within each flux arm * P value comparing the slope between the same reuse category of the two flux arms.Average Acute (first six months) and Chronic Slopes (> 6 months) of Predialysis β2M Concentration according to Reuse Quartile and Membrane Flux.