Table 3. Association of eGFR Calculation Method With Time to Achievement of an eGFR Less Than 20 mL/min/1.73 m².

	Overall	Baseline eGFR (CKD-EPIRC), mL/min/1.73 m2
		<30	30 to <45	45 to <60	≥60
CKD-EPIRC
No. at riska	1616	278	605	498	235
No. of events	462	158	197	87	20
Incidence rate, per 100 person-years (95% CI)	4.8 (4.4 to 5.3)	22.2 (18.6 to 25.8)	6.2 (5.4 to 7.1)	2.4 (1.9 to 2.8)	1.0 (0.6 to 1.4)
CKD-EPIWRC
No. at riska	1616	278	605	498	235
No. events	589	199	253	112	25
Incidence rate, per 100 person-years (95% CI)	6.5 (6 to 7.1)	41.2 (33.1 to 49.2)	8.6 (7.5 to 9.6)	3.1 (2.6 to 3.7)	1.3 (0.8 to 1.8)
CKD-EPICYS
No. at riska	1616	278	605	498	235
No. of events	448	155	189	87	17
Incidence rate, per 100 person-years (95% CI)	4.9 (4.4 to 5.3)	22.9 (18.5 to 27.2)	6.2 (5.3 to 7.0)	2.4 (2.0 to 2.9)	0.9 (0.5 to 1.3)
Difference in incidence rate, per 100 person-years (95% CI)b
CKD-EPIWRC – CKD-EPIRC	1.7 (1.4 to 2.0)	19.0 (13.3 to 24.7)	2.3 (1.8 to 2.9)	0.8 (0.5 to 1.0)	0.3 (0.0 to 0.5)
CKD-EPICYS – CKD-EPIRC	0.0 (−0.3 to 0.4)	0.7 (−2.6 to 3.9)	−0.1 (−0.7 to 0.6)	0.1 (−0.3 to 0.5)	−0.1 (−0.6 to 0.3)
Hazard ratioc
CKD-EPIWRC vs CKD-EPIRC	1.35 (1.29 to 1.41)d	1.81 (1.61 to 2.03)	1.38 (1.28 to 1.48)	1.32 (1.19 to 1.46)	1.26 (1.03 to 1.53)
CKD-EPICYS vs CKD-EPIRC	1.01 (0.94 to 1.08)e	1.02 (0.89 to 1.18)	1.00 (0.9 to 1.11)	1.05 (0.89 to 1.25)	0.89 (0.56 to 1.42)

Abbreviations: CKD, chronic kidney disease; CKD-EPI_CYS, cystatin C–based CKD-EPI eGFR; CKD-EPI_RC, creatinine-based CKD-EPI eGFR calculated with the race coefficient; CKD-EPI_WRC, creatinine-based CKD-EPI eGFR calculated without the race coefficient; eGFR, estimated glomerular filtration rate.

^aIncludes all participants with an eGFR (CKD-EPI_RC) of at least 20 mL/min/1.73 m² at study entry.

^bDifference in incidence rates per 100 person-years without minus with the race coefficient.

^cInstantaneous risk of an eGFR less than 20 mL/min/1.73 m² associated with use of the race coefficient.

^dP < .001.

^eP = .85.