Table 2.

Comparison of Estimated to Measured GFR Before and After Bariatric Surgery

BEFORE SURGERY	Expressed as ml/min	Expressed as ml/min/1.73
Bias- median difference*
MDRD	−9.0	−7.0
CKD-EPIcreat	−18.2	−13.5
CKD-EPIcystC	22.6	15.6
CKD-EPIcreat-cystC	1.6	1.0
Precision- IQR of difference*
MDRD	41.3	33.8
CKD-EPIcreat	46.9	33.0
CKD-EPIcystC	45.1	36.3
CKD-EPIcreat-cystC	35.0	28.4
Accuracy- root mean squared error
MDRD	0.34	0.26
CKD-EPIcreat	0.37	0.27
CKD-EPIcystC	0.46	0.34
CKD-EPIcreat-cystC	0.34	0.26
Accuracy- %
P15
MDRD	30.6	30.6
CKD-EPIcreat	44.4	44.4
CKD-EPIcystC	30.6	30.6
CKD-EPIcreat-cystC	41.7	41.7
P30
MDRD	72.2	72.2
CKD-EPIcreat	58.3	58.3
CKD-EPIcystC	52.8	52.8
CKD-EPIcreat-cystC	80.6	80.6
AFTER SURGERY
Bias- median difference*
MDRD	−18.5	−15.2
CKD-EPIcreat	−20.0	−18.7
CKD-EPIcystC	18.2	15.6
CKD-EPIcreat-cystC	−4.7	−3.9
Precision- IQR of difference*
MDRD	27.0	30.4
CKD-EPIcreat	33.0	29.6
CKD-EPIcystC	28.4	29.9
CKD-EPIcreat-cystC	21.6	23.4
Accuracy- root mean squared error
MDRD	0.36	0.30
CKD-EPIcreat	0.36	0.30
CKD-EPIcystC	0.35	0.30
CKD-EPIcreat-cystC	0.27	0.23
Accuracy- %
P15
MDRD	30.6	30.6
CKD-EPIcreat	30.6	30.6
CKD-EPIcystC	27.8	27.8
CKD-EPIcreat-cystC	58.3	58.3
P30
MDRD	55.6	55.6
CKD-EPIcreat	52.8	52.8
CKD-EPIcystC	66.7	66.7
CKD-EPIcreat-cystC	83.3	83.3

IQR, interquartile range; 1-P₁₅, percentage of estimates that differed from mGFR by more than 15%; 1-P₃₀, percentage of estimates that differed from mGFR by more than 30%

^*in ml/min for left column and ml/min/1.73m² for right column