Table 3. Subgroup analysis and meta-analysis.

Study characteristics	No	sensitivity	specificity	DOR	Chi2 test of heterogeneity	P value for heterogeneity	P-value
Total	12	0.53 (0.39–0.67)	0.88 (0.83–0.92)	8.70 (4.80.-15.78)	181.08
Field strength							0.2326
1.5T	9	0.54 (0.39–0.70)	0.86 (0.81–0.91)	7.34 (3.81–14.15)	170.72	< 0.001
3.0T	3	0.50 (0.22–0.79)	0.94 (0.89–0.99)	15.9 (10.27–24.62)	0.05	0.947
Coil							0.796
Without endorectal coil	8	0.55 (0.38–0.72)	0.88 (0.83–0.94)	10.11 (4.68–21.85)	153.44	< 0.001
With endorectal coil	4	0.49 (0.25–0.73)	0.89 (0.81–0.96)	7.22 (3.18–16.37)	28.02	< 0.001
Blind							0.5910
Unblind	5	0.51 (0.29–0.73)	0.87 (0.80–0.95)	8 (3.87–16.55)	35.20	< 0.001
Blind	7	0.55 (0.37–0.73)	0.89 (0.84–0.94)	10.10 (4.24–24.03)	145.55	< 0.001
Patient enrollment							0.1051
Non-consecutive or unclear	4	0.69 (0.50–0.88)	0.90 (0.83–0.96)	19.37 (5.49–68.36)	43.68	< 0.001
consecutive	8	0.45 (0.30–0.60)	0.88 (0.82–0.93)	6.12 (3.98–9.39)	52.13	< 0.001
Methods							0.0093
Traditional methods	5	0.36 (0.33–0.39)	0.89 (0.88–0.90)	8.62 (5.6–12.26)	14.71	0.005
Semi-parametric methods	3	0.48 (0.42–0.54)	0.72 (0.67–0.77)	2.75 (1.20–6.57)	9.77	0.008
parametric methods	4	0.68 (0.49–0.88)	0.90 (0.84–0.96)	19.92 (4.63–85.61)	91.99	< 0.001

Abbreviations: DOR: diagnostic odds ratio.