Background
Methods
Patients
GFR measurements
Biochemical measurements
Estimation of GFR
eGFR method | Equation |
---|---|
7MDRD | 170 × (Scr)-0.999 × (Age)-0.176 × 0.762 (if female) × 1.180 (if black) × (BUN)-0.170 × (Alb)0.318
|
aMDRD | 186 × (Scr)-1.154 × (Age)-0.203 × 0.742 (if female) × 1.212 (if black) |
re-aMDRD | 175 × (Scr)-1.154 × (Age)-0.203 × 0.742 (if female) × 1.212(if black) |
CKD-EPIcr | |
Female; Scr ≤ 0.7 mg/dl | 144 × (Scr/0.7)−0.329 × 0.993Age [×1.159 if black] |
Female; Scr > 0.7 mg/dl | 144 × (Scr/0.7)−1.209 × 0.993Age [×1.159 if black] |
Male; Scr ≤ 0.9 mg/dl | 141 × (Scr/0.9)−0.411 × 0.993Age [×1.159 if black] |
Male; Scr > 0.9 mg/dl | 141 × (Scr/0.9)−1.209 × 0.993Age [×1.159 if black] |
CKD-EPIcys | |
Female or Male; Scys ≤ 0.8 mg/dl | 133 × (Scys/0.8)−0.499 × 0.996Age [×0.932 if female] |
Female or Male; Scys > 0.8 mg/dl | 133 × (Scys/0.8)−1.328 × 0.996Age [×0.932 if female] |
CKD-EPIcr-cys | |
Female; | |
Scr ≤ 0.7 mg/dl; Scys ≤ 0.8 mg/dl | 130 × (Scr/0.7)−0.248 × (Scys/0.8)−0.375 × 0.995Age [×1.08 if black] |
Scr ≤ 0.7 mg/dl; Scys > 0.8 mg/dl | 130 × (Scr/0.7)−0.248 × (Scys/0.8)−0.711 × 0.995Age [×1.08 if black] |
Scr > 0.7 mg/dl; Scys ≤ 0.8 mg/dl | 130 × (Scr/0.7)−0.601 × (Scys/0.8)−0.375 × 0.995Age [×1.08 if black] |
Scr > 0.7 mg/dl; Scys > 0.8 mg/dl | 130 × (Scr/0.7)−0.601 × (Scys/0.8)−0.711 × 0.995Age [×1.08 if black] |
Male; | |
Scr ≤ 0.9 mg/dl; Scys ≤ 0.8 mg/dl | 135 × (Scr/0.9)−0.207 × (Scys/0.8)−0.375 × 0.995Age [×1.08 if black] |
Scr ≤ 0.9 mg/dl; Scys > 0.8 mg/dl | 135 × (Scr/0.9)−0.207 × (Scys/0.8)−0.711 × 0.995Age [×1.08 if black] |
Scr > 0.9 mg/dl; Scys ≤ 0.8 mg/dl | 135 × (Scr/0.9)−0.601 × (Scys/0.8)−0.375 × 0.995Age [×1.08 if black] |
Scr > 0.9 mg/dl; Scys > 0.8 mg/dl | 135 × (Scr/0.9)−0.601 × (Scys/0.8)−0.711 × 0.995Age [×1.08 if black] |
Statistical analysis
Results
Characteristics of the population
Variable | Mean ± SD (n = 245) or n[%] |
---|---|
Male gender (n[%]) | 131(53.5 %) |
Age (years) | 51.6 ± 14.2 |
Weight (kg) | 62.0 ± 12.1 |
Height (cm) | 163.9 ± 7.2 |
BMI (kg/m2) | 23.0 ± 3.6 |
BSA (m2) | 1.7 ± 0.2 |
Serum creatinine (mg/dl) | 1.2 ± 1.1 |
Serum cystatin C (mg/l) | 1.4 ± 0.7 |
Serum urea (mg/dl) | 18.0 ± 10.8 |
Serum albumin (g/dl) | 3.7 ± 0.5 |
Measured GFR (ml/min/1.73 m2) | 67 ± 24 |
Association and agreement between estimated GFR and measured GFR
Equation | R | ROCAUC
| Sensitivity |
---|---|---|---|
7MDRD | 0.681 | 0.816 | 0.72 |
aMDRD | 0.672 | 0.802 | 0.71 |
re-aMDRD | 0.672 | 0.802 | 0.71 |
CKD-EPIcr | 0.696 | 0.816 | 0.72 |
CKD-EPIcys | 0.675 | 0.833 | 0.73 |
CKD-EPIcr-cys | 0.720 | 0.847 | 0.74 |
Equation | Bias | Precision | Accuracy(%) | ||
---|---|---|---|---|---|
≤15 % | ≤30 % | ≤50 % | |||
7MDRD | 12.14** | 23.33** | 34.29** | 57.55** | 78.37** |
aMDRD | 14.77** | 24.65** | 29.80** | 53.47** | 74.69** |
re-aMDRD | 9.96** | 23.33** | 32.65** | 60.41** | 80.41** |
CKD-EPIcr | 13.51** | 21.58** | 30.61** | 53.88** | 78.78** |
CKD-EPIcys | −4.24** | 20.32** | 38.78** | 67.76 | 88.16 |
CKD-EPIcr-cys | 2.98 | 19.31 | 44.49 | 69.39 | 87.35 |
Performance of equations in subgroups
Variable | Subgroup | 7MDRD | aMDRD | re-aMDRD | CKD-EPIcr | CKD-EPIcys | CKD-EPIcr-cys | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
B | P | A(30 %) | B | P | A(30 %) | B | P | A(30 %) | B | P | A(30 %) | B | P | A(30 %) | B | P | A(30 %) | ||
GFR (ml/min/1.73 m2) | <60 | 13.83 | 24.39 | 40.86 | 15.20 | 25.13 | 39.78 | 11.82 | 23.57 | 43.01 | 14.88 | 23.90 | 37.63 | 0.27 | 19.33 | 52.69 | 5.49 | 19.83 | 51.61 |
60–90 | 13.69 | 19.51 | 64.86 | 16.84 | 21.39 | 59.46 | 11.46 | 20.19 | 68.47 | 16.92 | 18.21 | 54.95 | −2.15 | 19.45 | 76.58 | 5.90 | 17.64 | 76.58 | |
>90 | 4.08 | 28.73 | 75.61 | 8.18 | 30.63 | 68.29 | 1.68 | 28.91 | 78.05 | 1.19 | 20.60 | 87.80 | −20.11 | 17.39 | 78.05 | −10.62 | 16.94 | 90.24 | |
Age (year) | <45 | 17.39 | 28.23 | 55.22 | 18.48 | 29.66 | 50.75 | 12.87 | 27.96 | 61.19 | 19.25 | 24.86 | 47.76 | −1.24 | 22.72 | 71.64 | 6.92 | 22.09 | 64.18 |
45–60 | 10.48 | 21.54 | 59.29 | 13.76 | 23.13 | 56.64 | 8.92 | 21.91 | 64.60 | 12.44 | 20.14 | 56.64 | −4.66 | 19.96 | 72.57 | 2.31 | 18.00 | 75.22 | |
>60 | 9.61 | 20.04 | 12.70 | 12.70 | 21.28 | 50.77 | 8.77 | 20.39 | 52.31 | 9.45 | 19.39 | 55.38 | −6.60 | 18.16 | 55.38 | 0.07 | 18.05 | 64.62 | |
Gender | Male | 11.80 | 23.19 | 64.12 | 14.53 | 24.31 | 56.49 | 9.83 | 22.85 | 64.12 | 12.24 | 20.12 | 59.45 | −4.30 | 20.33 | 67.18 | 2.49 | 18.47 | 73.28 |
Female | 12.52 | 23.59 | 50.00 | 15.05 | 25.13 | 50.00 | 10.11 | 23.96 | 56.14 | 14.97 | 23.15 | 47.37 | −4.17 | 20.40 | 68.42 | 3.54 | 20.30 | 64.91 | |
Number of obstructed kidney | Unilateral | 15.47 | 23.16 | 58.43 | 18.4 | 24.19 | 54.82 | 13.17 | 23.01 | 63.86 | 16.32 | 20.21 | 57.23 | −2.74 | 19.87 | 72.29 | 5.29 | 18.59 | 74.70 |
Bilateral | 5.14 | 22.24 | 55.7 | 7.15 | 23.99 | 50.63 | 3.22 | 22.66 | 53.16 | 7.61 | 23.27 | 46.84 | −7.38 | 21.03 | 58.23 | −1.88 | 20.00 | 58.23 | |
Disease duration | ≥3 months | 11.19 | 25.75 | 60.61 | 13.52 | 26.83 | 54.55 | 8.62 | 25.48 | 65.91 | 16.13 | 20.43 | 47.79 | −3.13 | 18.47 | 73.45 | 4.65 | 17.13 | 70.80 |
<3 months | 13.24 | 20.2 | 53.98 | 16.24 | 21.73 | 52.21 | 11.53 | 20.54 | 53.98 | 11.28 | 22.36 | 59.09 | −5.19 | 21.81 | 62.88 | 1.55 | 20.96 | 68.18 |