Table 1.
Study and clinical characteristics
| Development & Internal Validation Studies |
External Validation (Paris) | Total Sample | |||||
|---|---|---|---|---|---|---|---|
| MDRD | AASK | CSG | Development | Internal Validation | |||
| Study Characteristics | |||||||
| Type | RCT | RCT | RCT | - | - | CP | - |
| Year | 1989–1992 | 1995–1998 | 1987–1992 | - | - | 2004–2005 | - |
| Filtration marker | iothalamate | iothalamate | iothalamate | EDTA | |||
| Clearance method | Urinary | Urinary | Urinary | Urinary | |||
| Population characteristics | |||||||
| Sample size | 1047 | 1647 | 286 | 1935 | 1045 | 438 | 3418 |
| Age, years | 52 (13) | 54 (10) | 34 (8) | 51 (13) | 51 (12) | 59 (15) | 52 (13) |
| Female | 39% | 36% | 47% | 37% | 40% | 29% | 37% |
| Black | 10% | 100% | 8% | 61% | 57% | 8% | 53% |
| White | 83% | 0% | 91% | 37% | 40% | 79% | 43% |
| Other | 7% | 0% | 1% | 2% | 3% | 13% | 4% |
| Diabetes | 6% | 0% | 100% | 12% | 11% | 22% | 13% |
| Height, m | 171 (10) | 171 (10) | 169 (9) | 171 (10) | 171 (10) | 168 (9) | 171 (10) |
| Weight, Kg | 79(16) | 90(21) | 73(14) | 85(20) | 83(20) | 74(16) | 83(20) |
| Body Mass Index, kg/m2 | 27(4) | 31(7) | 25(5) | 29(6) | 29(6) | 26(5) | 29(6) |
| Body Surface Area, m2 | 1.9(0.2) | 2.0 (0.2) | 1.8(0.2) | 2.0 (0.2) | 1.9(0.2) | 1.8(0.2) | 1.9 (0.2) |
| Albumin, g/dL | 4(0.4) | 4.3(0.4) | 3.7(0.5) | 4.1(0.4) | 4.1(0.4) | 4.1(0.5) | 4.1(0.4) |
| GFR, ml/min/1.73m2 | 33 (14) | 57 (23) | 75 (33) | 51 (26) | 50 (26) | 34 (17) | 48 (25) |
| (5th–95th %ile) | 13–57 | 22–98 | 24–134 | 15–98 | 16–95 | 11–66 | 15–95 |
| Standardized Serum Creatinine, mg/dL | 2.5 (1.1) | 1.9(0.9) | 1.4(0.6) | 2.1(1.0) | 2(1.0) | 2.5(1.2) | 2.1(1.1) |
| Serum Cystatin, mg/L | 2.2 (0.8) | 1.5 (0.7) | 1.4 (0.7) | 1.8 (0.8) | 1.8 (0.8) | 2.2 (0.8) | 1.8 (0.8) |
MDRD Study, Modification of Diet in Renal Disease Study; AASK, African American Study of Kidney Diseases and Hypertension; CSG, Collaborative Study Group: Captopril in Diabetic Nephropathy Study; RCT, randomized clinical trial; Scr, serum creatinine; SD, standard deviation; GFR is measured in ml/min per 1.73 m2; Mean (SD) reported for continuous data ; Percents for dichotomous data. To convert albumin from g/dL to g/L, multiply by 10. To convert GFR from mL/min/1.73 m2 to mL/sec per 1.73 m2, multiply by 0.01666. To convert serum creatinine from mg/dL to umol/L, multiply by 88.4. To convert cystatin C from mg/L to nmol/L, multiply by 74.9‥