3. Subgroup and sensitivity analysis for T1a versus T1b gastric tumors.

Variable	Category	Studies	Sensitivity (95% CI)	Specificity (95% CI)	P value*
Sample size	>100	8	0.90 (0.84 to 0.96)	0.67 (0.50 to 0.85)	0.49
	<100	12	0.85 (0.76 to 0.93)	0.79 (0.67 to 0.91)
Year of publication	2000 or later	11	0.90 (0.84 to 0.95)	0.70 (0.55 to 0.85)	0.59
	before 2000	9	0.84 (0.75 to 0.94)	0.79 (0.66 to 0.93)
Country	Western	1	1.00 (0.40 to 1.00)	1.00 (0.69 to 1.00)	N/A
	Eastern	19	0.88 (0.81 to 0.92)	0.73 (0.61 to 0.82)
EUS array	Radial	18	0.89 (0.82 to 0.93)	0.72 (0.59 to 0.82)	N/A
	Linear	1	0.50 (0.07 to 0.93)	0.88 (0.64 to 0.99)
Tumor site	Cardia region	1	0.50 (0.07 to 0.93)	0.88 (0.64 to 0.99)	N/A
	Any site	19	0.88 (0.82 to 0.92)	0.74 (0.61 to 0.83)
Quality	High	18	0.84 (0.79 to 0.89)	0.75 (0.64 to 0.86)	0.05
	Low	2	0.98 (0.96 to 1.00)	0.64 (0.26 to 1.00)

CI: confidence interval
 EUS: endoscopic ultrasonography
 *P values are from likelihood ratio test for model with and without the covariate, to identify diagnostic performance differences across variable categories.