Longitudinal assessment of measured and estimated glomerular filtration-rate in autosomal dominant polycystic kidney disease: Real practice experience

Table 2 Concordance correlation coefficient between the measured glomerular filtration rate (used as reference method) and the estimated glomerular filtration rate (by chronic kidney disease epidemiology collaboration, modification of diet in renal disease and creatinine clearance formulas) in the overall study sample and according to the median split baseline measured glomerular filtration rate groups

	mGFR (reference), overall study sample (n = 37)
	CCC (95%CI)	Precision	Accuracy
CKD-EPI	0.576 (0.318-0.754)	0.585	0.983
MDRD	0.457 (0.223-0.641)	0.582	0.786
CrCl	0.598 (0.376-0.755)	0.697	0.858
	mGFR ≤ 80 (n = 17)
	CCC (95%CI)	Precision	Accuracy
CKD-EPI	0.315 (-0.038 to 0.599)	0.425	0.741
MDRD	0.356 (-0.069 to 0.672)	0.414	0.862
CrCl	0.418 (0.064-0.679)	0.599	0.698
	mGFR > 80 (n = 20)
	CCC (95%CI)	Precision	Accuracy
CKD-EPI	0.429 (0.069-0.690)	0.515	0.833
MDRD	0.277 (0.033-0.490)	0.529	0.524
CrCl	0.315 (-0.037 to 0.597)	0.423	0.745

CCC: Concordance correlation coefficient; CKD-EPI; Chronic kidney disease epidemiology collaboration; CrCl: Creatinine clearance; MDRD: Modification of diet in renal disease; mGFR: Measured glomerular filtration rate.