Table 1 The expression of five equations basing on SCr in the study

2009

CKD- EPI equation

141 × (SCr/0.9)^−0.411 ×    0. 993^Age(Male, SCr ≤ 0.9)

141 × (SCr/0.9)^−1.209 × 0. 993^Age(Male, SCr > 0.9)

144 × (SCr/0.7)^−0.329 × 0. 993^Age(Female, SCr ≤ 0.7)

144 × (SCr/0.7)^−1.209 × 0. 993^Age(Female, SCr > 0.7)

2011

LMR equation

e^{X – 0.0158 ∗ Age + 0.438 ∗ In(Age)}

X = 2.56 + 0.00968 ∗ (2 – SCr)(Male, Scr   < 2.0)

X = 2.56 – 0.926 ∗ In(SCr/2) (Male, Scr ≥ 2.0)

X = 2.50 + 0.0121 ∗ (1.7 – SCr) (Female, SCr  <  1.7)

X = 2.50 – 0.926 ∗ In (SCr/1.7) (Female, SCr ≥ 1.7)

2012

BIS1 equation

3736 × SCr^−0.870 × age^−0.950 × (0.82 Female)

2016

FAS equation

107.3/(SCr/0.9) × [0. 988^{(age − 40)}age > 40 years](Male)

107.3/(SCr/0.7) × [0. 988^{(age − 40)}age > 40 years](Female)

2020

EKFC equation

107.3 × (SCr/0.9)^−0.322 × [0.990^{(age − 40)}age > 40 years] (Male, SCr  <  0.9)

107.3 × (SCr/0.9)^−1.132 × [0.990^{(age − 40)}age > 40 years] (Male, SCr ≥ 0.9)

107.3 × (SCr/0.7)^−0.322 × [0.990^{(age − 40)}age > 40 years](Female, SCr <  0.7)

107.3 × (SCr/0.7)^−1.132 × [0.990^{(age − 40)}age > 40 years] (Female, SCr ≥ 0.7)