Table 2.
Discrimination of ESKD Events by eGFR Levels and Kidney Failure Risk Equation Scores Classified Using Various Equations
| Discrimination of cut-off points |
CKD-EPI Equations to Estimate GFR | ||||
|---|---|---|---|---|---|
| Creatinine with Age, Sex, and Race |
Creatinine with Age and Sex |
Cystatin C with Age and Sex |
Creatinine and Cystatin C with Age, Sex and Race |
Creatinine and Cystatin C with Age and Sex |
|
| Black Participants | |||||
| Estimated glomerular filtration rate <20 mL/min/1.73 m2 | |||||
| Sensitivity (95% CI) | 0.57 (0.52-0.61) | 0.66 (0.61-0.70) | 0.49 (0.44-0.54) | 0.59 (0.53-0.64) | 0.59 (0.54-0.64) |
| Specificity (95% CI) | 0.96 (0.96-0.97) | 0.95 (0.94-0.95) | 0.95 (0.94-0.96) | 0.95 (0.95-0.96) | 0.95 (0.94-0.96) |
| Youden’s index (95% CI) * | 0.53 (0.48-0.57) | 0.60 (0.56-0.65) | 0.44 (0.39-0.49) | 0.54 (0.49-0.59) | 0.54 (0.49-0.59) |
| Kidney Failure Risk Equation predicted 2-year ESKD risk >20% | |||||
| Sensitivity (95% CI) | 0.73 (0.69-0.78) | 0.78 (0.74-0.82) | 0.69 (0.64-0.73) | 0.74 (0.70-0.78) | 0.75 (0.71-0.79) |
| Specificity (95% CI) | 0.95 (0.95-0.96) | 0.94 (0.93-0.95) | 0.95 (0.94-0.96) | 0.95 (0.94-0.95) | 0.94 (0.94-0.95) |
| Youden’s index (95% CI) * | 0.69 (0.64-0.73) | 0.72 (0.68-0.76) | 0.63 (0.59-0.68) | 0.69 (0.64-0.73) | 0.70 (0.65-0.74) |
| Non-Black Participants | |||||
| Estimated glomerular filtration rate <20 mL/min/1.73 m2 | |||||
| Sensitivity (95% CI) | 0.51 (0.46-0.55) | 0.42 (0.38-0.47) | 0.42 (0.37-0.46) | 0.50 (0.46-0.54) | 0.45 (0.40-0.49) |
| Specificity (95% CI) | 0.97 (0.96-0.97) | 0.98 (0.98-0.98) | 0.96 (0.96-0.97) | 0.96 (0.96-0.97) | 0.97 (0.97-0.98) |
| Youden’s index (95% CI) * | 0.48 (0.43-0.52) | 0.40 (0.36-0.45) | 0.38 (0.33-0.42) | 0.46 (0.42-0.51) | 0.42 (0.37-0.46) |
| Kidney Failure Risk Equation predicted 2-year ESKD risk >20% | |||||
| Sensitivity (95% CI) | 0.73 (0.68-0.77) | 0.69 (0.64-0.73) | 0.68 (0.63-0.72) | 0.74 (0.70-0.78) | 0.69 (0.65-0.73) |
| Specificity (95% CI) | 0.96 (0.95-0.96) | 0.97 (0.96-0.97) | 0.96 (0.95-0.96) | 0.95 (0.95-0.96) | 0.96 (0.96-0.97) |
| Youden’s index (95% CI) * | 0.68 (0.64-0.72) | 0.66 (0.61-0.70) | 0.63 (0.59-0.68) | 0.70 (0.65-0.73) | 0.65 (0.61-0.69) |
CI = confidence interval; CKD-EPI = Chronic Kidney Disease Epidemiology Collaboration; eGFR = estimated glomerular filtration rate; ESKD = end-stage kidney disease
*
Youden’s index is summary metric of validity that considers both sensitivity and specificity, and is calculated as: [sensitivity] + [specificity] – 1