Table 2.

Subgroup analysis of the included studies based on the differences of the purpose of testing and the positive result definition (95% CI, %)

	Pooled sensitivity	Pooled specificity	Pooled positive likelihood ratio	Pooled negative likelihood ratio	Pooled diagnostic DOR	AUC
Overall	60 (53-67)	92 (90-94)	8.0 (5.8-11.0)	0.43 (0.36-0.52)	19 (11-30)	0.88 (0.85-0.91)
The purpose of testing
CRC screening	64 (59-69)	92 (91-93)	8.5 (7.1-10.1)	0.39 (0.33-0.45)	22 (16-30)	0.92 (0.89-0.94)
Assessment of recurrence	54 (42-67)	93 (88-96)	7.4 (3.9-14.2)	0.49 (0.37-0.66)	15 (6-37)	0.85 (0.81-0.88)
The definition of positive results
At least one PCR replicate	59 (50-67)	91 (89-93)	6.6 (4.6-9.5)	0.45 (0.36-0.56)	15 (8-26)	0.87 (0.84-0.90)
Set a specific threshold	61 (49-72)	94 (87-96)	10.5 (6.1-17.9)	0.42 (0.31-0.57)	25 (12-55)	0.91 (0.88-0.93)

AUC: Area under the curve; CRC: Colorectal cancer; CI: Confidence interval; PCR: Polymerase chain reaction.