Table 3.

Diagnostic indices of the systems for follicular thyroid neoplasms depending on predictive classifications. Classifiable nodules of each system were included

Ultrasound-based malignancy risk stratification systems	Sensitivity(%)	Specificity(%)	PPV(%)	NPV(%)	AUC	p
ATA	23.3 (13.4–36.0)	87.7 (82.9–91.5)	31.1 (20.4–44.3)	82.7 (80.5–84.7)	0.555 (0.498–0.611)	p = 0.062
AACE/ACE/AME	98.4 (91.3–99.9)	3.84 (1.9–7.0)	19.6 (19.0–20.3)	90.9 (56.6–98.7)	0.511 (0.455–0.567)	p = 0.266
K-TIRADS	30.3 (19.6–42.9)	84.3 (79.3–88.5)	32.7 (23.5–43.6)	82.7 (80.2–85.0)	0.573 (0.517–0.627)	p = 0.017a
EU-TIRADS	33.9 (22.3–47.0)	84.0 (78.9–88.3)	33.9 (24.7–44.5)	84.0 (81.3–86.3)	0.589 (0.533–0.644)	p = 0.006a
ACR-TIRADS	38.8 (27.1–51.5)	80.2 (74.8–84.8)	33.3 (25.4–42.4)	83.7 (80.7–86.2)	0.595 (0.540–0.648)	p = 0.004a
C–TIRADS	26.9 (16.8–39.1)	95.4 (92.1–97.6)	60.0 (43.2–74.7)	83.6 (81.5–85.5)	0.611 (0.556–0.664)	p < 0.001a

Numbers in parentheses are 95% confidence intervals

^aThere was no significant difference between the AUCs of the above four systems (p > 0.05)

Abbreviations: PPV positive predictive value; NPV negative predictive value; ATA 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer; AACE/ACE/AME American Association of Clinical Endocrinologists, American College of Endocrinology, and Associazione Medici Endocrinology Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules (2016 Update); EU-TIRADS European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults; K-TIRADS Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations; ACR-TIRADS American College of Radiology Thyroid Imaging Reporting and Data System; C-TIRADS 2020 Chinese Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules