The theoretical constructs indicate that, for a 70kg high transport anephric patient, adequate dialysis requires a weekly KtN of 2.0 2.25 (1–5). The prospective cohort studies, with one exception, suggest that better survival requires a weekly KtN >1.89 (7–11). Multivariate analyses confirm the statistical association of patient survival with higher Kt/V(14–17) and with higher CCr (16,17). The use of initial values in one study (15), mean values in two studies (14,16), and time -dependent values in another (17) makes comparison difficult. In general, higher values are associated with better survival and are consistent with the values suggested by theoretical constructs (i.e., KtN 2.0 2.25).