Table 1.
Patient and nodule characteristics by surgery status
| Characteristic | No Surgery (n = 251) | Surgery (n = 38) | P Valuea |
|---|---|---|---|
| Age at biopsy, mean (SD) | 55.8 (13.6) | 49.5 (15.0) | 0.02 |
| Gender, female (%) | 192 (76.5) | 29 (76.3) | 0.91 |
| Bethesda category (%) | 0.99 | ||
| III | 187 (74.5) | 28 (73.7) | |
| IV | 64 (25.5) | 10 (26.3) | |
| Hürthle cell changes (%) | 29 (11.6) | 5 (13.2) | 0.11 |
| Race (%) | 0.99 | ||
| Caucasian | 209 (83.3) | 33 (86.8) | |
| African American | 32 (12.7) | 5 (13.2) | |
| Asian | 8 (3.2) | 0 (0) | |
| Hispanic | 1 (0.4) | 0 (0) | |
| Unknown | 1 (0.4) | 0 (0) | |
| ATA sonographic risk (%) | 0.69 | ||
| High | 14 (5.6) | 3 (7.9) | |
| Intermediate | 95 (37.8) | 12 (31.6) | |
| Low | 122 (48.6) | 22 (57.9) | |
| Very low | 12 (4.8) | 1 (2.6) | |
| Unknown | 8 (3.2) | 0 (0) | |
| TIRAD risk (%) | 0.87 | ||
| 5 | 12 (4.8) | 3 (7.9) | |
| 4 | 99 (39.4) | 16 (42.1) | |
| 3 | 108 (43.0) | 15 (39.5) | |
| 2 | 18 (7.2) | 3 (7.9) | |
| 1 | 6 (2.4) | 1 (2.6) | |
| Unknown | 8 (3.2) | 0 (0) | |
| Multinodular (%) | 171 (68.1) | 30 (78.9) | 0.16 |
| Presence of Afirma suspicious nodule outside the index nodule (%) | 4 (1.6) | 7 (18.4) | <0.001 |
| Compressive symptoms (%) | 17 (6.8) | 15 (39.5) | <0.001 |
| Initial maximum nodule size (cm), median (IQR) | 2.0 (1.5, 2.8) | 2.8 (1.8, 3.6) | <0.001 |
| Initial nodule volume (cm3), median (IQR) | 1.8 (0.8, 4.1), n = 244 | 4.5 (1.4, 10.1) | <0.001 |
| Last follow-up maximum nodule size (cm), median (IQR) | 2.0 (1.5, 2.8), n = 149 | 3.4 (2.7, 3.7), n = 18 | 0.001 |
| Last follow-up nodule volume (cm3), median (IQR) | 2.0 (0.9, 4.6), n = 149 | 6.9 (3.7, 14.2), n = 18 | 0.02 |
| Change in nodule size at last follow-up (cm), median (IQR) | 0.0 (–0.2, 0.2), n = 149 | 0.3 (0.0, 0.5), n = 18 | 0.17 |
| Change in nodule volume at last follow-up (cm3), median (IQR) | 0.1 (–0.4, 0.9), n = 143 | 0.5 (0.0, 4.4), n = 18 | 0.06 |
Abbreviations: ATA, American Thyroid Association; IQR, interquartile range; SD, standard deviation; TIRAD, Thyroid Imaging Reporting and Data Systems.
aUnivariable Cox proportional hazards model, excludes missing/unknown values.