Stepwise multiple regression analysis of ln p-cresol plasma concentrations in peritoneal dialysis patients.

Sev use was the only variable left in the model because significant at the 0.10 level. The following variables of the original model were excluded because they did not meet the 0.10 significance level in the stepwise procedure: total clearance (β = 0.04, p = 0.77), rGFR (β = −0.07; p = 0.57), urine volume (β = 0.02; p = 0.88), total Kt/V (β = −0.06; p = 0.65), presence or absence of diabetes (β = −0.07; p = 0.55), nPCR (β = 0.01; p = 0.95), serum albumin (β = 0.003; p = 0.98), serum phosphate (β = −0.03; p = −0.82) and serum iPTH (β = −0.11; p = 0.40).