Towards equations for estimating glomerular filtration rate without demographic characteristics

Abstract

Creatinine eGFRcr(ASR) [current] 62 (48-75) 79 (73-86) 74 (68-80) eGFRcr(AS) [new] 60 (46-73) 73 (65-80) 69 (62-75) Cystatin C eGFRcys(AS) [current] 77 (65-87) 87 (81-93) 84 (79-89) Creatinine-cystatin C eGFRcr-cys(ASR) [current] 71 (58-83) 87 (81-93) 82 (76-88) eGFRcr-cys(AS) [new] 65 (52-77) 84 (78-90) 79 (73-85) Percent agreement (95% CI) within 20% of the mGFR, P 20 -% Creatinine eGFRcr(ASR) [current] 40 (27-54) 61 (53-69) 55 (48-62) eGFRcr(AS) [new] 35 (23-48) 53 (45-62) 48 (41-55) Cystatin C eGFRcys(AS) [current] 56 (42-69) 73 (65-80) 68 (61-75) Creatinine-cystatin C eGFRcr-cys(ASR) [current] 52 (38-65) 70 (63-78) 65 (58-72) eGFRcr-cys(AS) [new] 52 (38-65) 68 (61-76) 64 (57-71) Correct classification Percent agreement (95% CI) between the mGFR and eGFR categories -% Creatinine eGFRcr(ASR) [current] 60 (46-73) 70 (62-78) 67 (60-74) eGFRcr(AS) [new] 52 (37-65) 64 (56-73) 61 (54-68) Cystatin C eGFRcys(AS) [current] 65 (52-79) 73 (66-81) 71 (65-78) Creatinine-cystatin C eGFRcr-cys(ASR) [current] 67 (54-79) 74 (66-81) 72 (66-78) eGFRcr-cys(AS) [new] 62 (48-73) 75 (67-81) 71 (64-78) Abbreviations: eGFR, estimated glomerular filtration rate; mGFR, measured glomerular filtration rate. a The performance of each equation in estimating the GFR was evaluated in terms of bias, precision and accuracy, according to the methods described by Inker et al. (2012) 2 and Inker et al. (2021) 4 . b The values indicating the best two equations were italicized and made bold.c Accuracy was calculated as the RMSE relative to the mGFR, the percentage of estimates that differed from the mGFR by less than 30% (P 30 ), and the percentage that differed by less than 20% (P 20 ).