4. Diagnostic utility of TBSRTC.
| Variables | NIFTP=Ca | NIFTP≠Ca |
| TBSRTC, The Bethesda system for reporting thyroid cytopathology; NIFTP, noninvasive follicular thyroid neoplasms with papillary-like nuclear features; Ca, cancer; PPV, positive predictive values; NPV, negative predictive values. | ||
| True-positive cases (a) (n) | 721 | 720 |
| False-positive cases (b) (n) | 4 | 5 |
| False-negative cases (c) (n) | 15 | 14 |
| True-negative cases (d) (n) | 21 | 22 |
| Sensitivity [a/(a+c)] (%) | 98.0 | 98.1 |
| Specificity [d/(b+d)] (%) | 84.0 | 81.5 |
| PPV [a/(a+b)] (%) | 99.4 | 99.3 |
| NPV [d/(c+d)] (%) | 58.3 | 61.1 |
| Diagnostic accuracy [(a+d)/(a+b+c+d)] (%) | 97.5 | 97.5 |