| US, n (%)(n = 382) | No US, n (%)(n = 380) | Difference(%) | p Value | |
| Correct diagnosis | 247 (64.7) | 216 (56.8) | 7.9 | 0.027 |
| Intention-to-treat (ITT) analyses | US (n = 400) | No US (n = 399) | ||
| All excluded incorrect | 247 (61.8) | 216 (54.1) | 7.7 | 0.029 |
| All excluded correct | 265 (66.3) | 235 (58.9) | 8.4 | 0.032 |
| US correct, not US incorrect | 265 (66.3) | 216 (54.1) | 12.2 | <0.001 |
| US incorrect, not US correct | 247 (61.8) | 235 (58.9) | 2.9 | 0.410 |