Table 5.

Performance Characteristics of CT Colonography relative to Optical Colonoscopy to detect serrated v. conventional adenomas^1,2,

1. Serrated only, patient level
Performance Characteristic	Adenoma Size Category from Optical Colonoscopy
	≥6mm	≥10mm
Patient-Level Analyses3
Sensitivity	6/10 60.0 (29.6–90.4)*	3/4 75.0 (32.6–100)
Specificity	168/221 76.0 (70.4–81.6)*	171/227 75.3 (69.7–80.9)*
Negative Predicted Value	168/172 97.7 (95.4–99.9)	171/172 99.4 (98.3–100)
Positive Predicted Value	6/59 10.2 (2.5–17.9)*	3/59 5.1 (0–10.7)*

2. Serrated + mixed serrated and conventional adenoma, patient level
Performance Characteristic	≥6mm	≥10mm
Patient-Level
Sensitivity	6/11 54.6 (25.1–84.0)*	3/4 75.0 (32.6–100)
Specificity	167/220 75.9 (70.3–81.6)*	171/227 75.3 (69.7–80.9)*
Negative Predicted Value	167/172 97.1 (94.6–99.6)	171/172 99.4 (98.3–100)
Positive Predicted Value	6/59 10.2 (2.5–17.9)*	3/59 5.1 (0–10.7)*

3. Conventional adenoma only, patient level.
Performance Characteristic	≥6mm	≥10mm
Patient-Level
Sensitivity	16/25 64.0 (45.2–82.8)*	5/6 83.3 (53.5–100)
Specificity	163/206 79.1 (73.6–84.7)*	171/225 76.0 (70.4–81.6)*
Negative Predicted Value	163/172 94.8 (91.4–98.1)	171/172 99.4 (98.3–100)
Positive Predicted Value	16/59 27.1 (15.8–38.5)*	5/59 8.5 (1.4–15.6)*

¹Cell values include number/total number, performance characteristic estimate and two-sided 95% confidence intervals

²Optical colonoscopy results are from initial pass before results from virtual colonoscopy were revealed to gastroenterologist. CTC is defined as positive for a patient if at least one ≥6mm lesion as measured by CTC is detected.

³Adenoma size category represents maximum adenoma size per patient as determined by optical colonoscopy.

^*operating characteristics significantly less than 90% (p<.05).