Table 2 Bias, precision, and accuracy of first and second morning spot urine estimated protein excretion compared with 24-h proteinuria
24-h proteinuria mean (SD) mg/day/1.73m2 | n | Urine sample | Biasa mg/day/1.73m2 (95% CI) | Percent biasb % (95% CI) | Precisionc mg/day/1.73m2 (95% CI) | Accuracyd within 15%, % (95% CI) | Accuracyd within 30%, % (95% CI) | Accuracyd within 50%, % (95% CI) |
|---|---|---|---|---|---|---|---|---|
150 to 299 | 45 | first morning | −46 (− 77 to − 16) | − 28 (− 44 to − 11) | 102 (84 to 129) | 22 (12 to 36) | 56 (41 to 69) | 71 (57 to 82) |
201 (45) | second morning | −17 (− 37 to 3)* | −11 (− 21 to − 1)* | 67 (55 to 85)* | 36 (23 to 50)* | 71 (57 to 82)* | 89 (76 to 96) | |
Subgroup | ||||||||
CrCl ≥60 ml/min | 18 | first morning | −6 (− 59 to 46) | −9 (− 37 to 19) | 106 (80 to 159) | 17 (5 to 40) | 67 (44 to 84) | 89 (66 to 98) |
206 (42) | second morning | −5 (− 48 to 37) | −6 (− 26 to 15) | 85 (64 to 127) | 28 (12 to 51) | 61 (39 to 79) | 83 (60 to 95) | |
CrCl < 60 ml/min | 26 | first morning | −73 (− 109 to − 37) | −41 (− 61 to − 20) | 91 (72 to 125) | 26 (13 to 45) | 48 (31 to 66) | 59 (41 to 76) |
198 (48) | second morning | −25 (−45 to − 4)** | −14 (− 25 to − 3)** | 52 (41 to 71)** | 41 (25 to 59)* | 78 (59 to 89)* | 93 (76 to 99)* | |
300 to 999 | 65 | first morning | −2 (−64 to 59) | 1 (− 8 to 10) | 249 (212 to 301) | 38 (28 to 51) | 60 (48 to 71) | 91 (81 to 96) |
380 (54) | second morning | 16 (−30 to 64) | 2 (−6 to 10) | 189 (161 to 229) | 43 (32 to 55) | 74 (62 to 83) | 88 (77 to 94) | |
Subgroup | ||||||||
CrCl ≥60 ml/min | 23 | first morning | 75 (1 to 148) | 13 (−1 to 27) | 170 (131 to 241) | 22 (9 to 42) | 48 (29 to 67) | 96 (77 to 100) |
368 (54) | second morning | 71 (5 to 137) | 11 (−5 to 27) | 152 (118 to 215) | 39 (22 to 59)* | 70 (49 to 85)* | 87 (67 to 96) | |
CrCl < 60 ml/min | 42 | first morning | −44 (− 130 to 42) | −6 (− 17 to 5) | 275 (226 to 351) | 48 (33 to 62) | 67 (51 to 79) | 88 (75 to 95) |
388 (54) | second morning | −12 (−76 to 51) | −2 (− 11 to 7) | 202 (166 to 258) | 45 (31 to 60) | 76 (61 to 87)* | 88 (75 to 95) | |
≥1000 | 41 | first morning | 245 (23 to 467) | 9 (1 to 18) | 703 (577 to 899) | 44 (30 to 59) | 73 (58 to 84) | 98 (86 to 100) |
2226 (1175) | second morning | 168 (−54 to 390) | 6 (−4 to 15) | 704 (578 to 901) | 42 (28 to 57) | 78 (63 to 88) | 93 (80 to 98) | |
Subgroup | ||||||||
CrCl ≥60 ml/min | 13 | first morning | 354 (− 283 to 990) | 10 (−11 to 31) | 1054 (756 to 1740) | 31 (12 to 58) | 62 (35 to 82) | 100 (73 to 100) |
2082 (1398) | second morning | 312 (−89 to 712) | 16 (−1 to 32) | 663 (475 to 1094) | 38 (18 to 65) | 77 (49 to 93) | 92 (65 to 100) | |
CrCl < 60 ml/min | 28 | first morning | 195 (8 to 381) | 9 (−1 to 18) | 480 (380 to 653) | 50 (33 to 68) | 79 (60 to 90) | 96 (81 to 100) |
2292 (1078) | second morning | 101 (− 180 to 381) | 2 (−11 to 13) | 720 (569 to 980) | 43 (27 to 61) | 79 (60 to 90) | 93 (76 to 99) | |