Table 4.
Likelihood of each grading system predicting need for surgery
| Grading Systems (N=348) | Children Who Had Surgery (n=96) | LR+ | Sensitivity | Specificity | PPV |
|---|---|---|---|---|---|
| APD | |||||
| <6 mm | 2 (2.1) | 0.07 (0.01 to 0.28) | 2 (0.01 to 0.07) | 71.0 (65.1 to 76.2) | 2.67 (0.40 to 9.32) |
| ≥6–9 mm | 7 (7.3) | 0.28 (0.13 to 0.59) | 7.29 (2.99 to 14.4) | 74.2 (68.3 to 79.4) | 9.72 (4.02 to 19) |
| ≥9–15 mm | 22 (22.9) | 0.70 (0.46 to 1.05) | 22.9 (14.9 to 32.6) | 67.4 (61.3 to 73.2) | 21.1 (13.7 to 30.6) |
| >15 mm | 65 (67.7) | 5.33 (3.75 to 7.58) | 67.7 (57.3 to 76.8) | 87.3 (82.5 to 91.1) | 67.1 (56.7 to 76.2) |
| SFU grade | |||||
| 1 | — | — | — | — | — |
| 2 | 7 (7.3) | 0.15 (0.07 to 0.31) | 7.29 (2.99 to 14.4) | 50.7 (44.4 to 57.1) | 5.34 (2.18 to 10.7) |
| 3 | 23 (23.9) | 1.89 (1.17 to 3.05) | 23.9 (15.8 to 33.7) | 87.3 (82.5 to 91.1) | 41.8 (28.6 to 55.8) |
| 4 | 66 (68.8) | 6.19 (4.26 to 9) | 68.7 (58.4 to 77.8) | 88.8 (84.3 to 92.4) | 70.2 (59.9 to 79.2) |
| Combined grading system | |||||
| APD<6 mm, no/few dilated calyces | 2 (2.1) | 0.08 (0.02 to 0.30) | 2.08 (0.31 to 7.34) | 72.6 (66.6 to 78) | 2.82 (0.42 to 9.83) |
| APD<6 mm, with diffuse caliectiasis | — | — | — | — | — |
| APD≥6–9 mm, no/few dilated calyces | 1 (1.1) | 0.04 (0.01 to 0.32) | 1.04 (0.17 to 5.69) | 76.5 (70.8 to 81.6) | 1.67 (0.28 to 8.97) |
| APD≥6–9 mm, with diffuse caliectasis | 6 (6.2) | 2.62 (0.87 to 7.94) | 6.25 (2.34 to 13.1) | 97.6 (94.8 to 99.1) | 50 (21.2 to 78.7) |
| APD≥9–15 mm, no/few dilated calyces | 3 (3.1) | 0.14 (0.04 to 0.43) | 3.12 (0.69 to 8.87) | 77.3 (71.7 to 82.3) | 5.0 (1.1 to 13.9) |
| APD≥9–15 mm, with diffuse caliectiasis | 19 (19.8) | 2.0 (1.15 to 3.45) | 19.7 (12.3 to 29.1) | 90.0 (85.7 to 93.4) | 43.1 (28.3 to 58.9) |
| APD>15 mm, no/few dilated calyces | 1 (1.1) | 0.44 (0.05 to 3.59) | 1.04 (0.17 to 5.69) | 97.6 (94.8 to 99.1) | 14.2 (2.37 to 57.7) |
| APD>15 mm, with diffuse caliectasis | 64 (66.6) | 6.97 (4.71 to 10.3) | 66.7 (56.3 to 75.9) | 90.4 (86.3 to 93.6) | 71.1 (60.6 to 80.1) |
Values are n (%) or % (95% confidence interval). APD, anteroposterior diameter of the renal pelvis; SFU, Society for Fetal Urology; no/few dilated calyces, absence of dilation of minor calyces only; diffuse caliectasis, presence of dilation of major and minor calyces; 95% CI, 95% confidence interval; LR+, positive likelihood ratio; PPV, positive predictive value.