Table 1.

GFR estimating equations based on BTP developed by White³² and Pöge³³

Description	Development population	Equation
White Equation 1 (BTP & urea)	N = 163, kidney transplant patients	eGFR = 112.1 × BTP-0.662 × Urea-0.280 × (0.880 if female)
White Equation 2 (BTP & Cr)	N = 163, kidney transplant patients	eGFR = 167.8 x BTP-0.758 × Cr-0.204 × (0.871 if female)
Pöge BTP-formula 1 (BTP alone)	N = 85, kidney transplant patients	eGFR = 47.17 × BTP-0.7933
Pöge BTP-formula 2 (BTP & Cr)	N = 85, kidney transplant patients	eGFR = 974.31 × BTP-0.2594 × Cr-0.647
Pöge BTP-formula 3 (BTP & urea)	N = 85, kidney transplant patients	eGFR = 89.85 × BTP-0.5541 × Urea-0.3018

White and Pöge formulas utilize units of mg/L for BTP, mmol/L for creatinine, and mmol/L for urea.