Table 1.

Clinical characteristics of the included studies.

Study, format, nationality	Type of AIa	Type of endoscopy, diagnostic method of Helicobacter pylori infection	Number of cases in test dataset	Number of controls in test dataset	Age of patients in test dataset; gender in patients in test dataset (M/Fb)	TPc	FPd	FNe	TNf	Unit of analysis
Yasuda et al [10], retrospective, Japan	Support vector machine	LCIg; more than 2 different tests in each case (histology, serum antibody, stool antigen, urea breath test)	42 H pylori patients	63 controls (46 posteradication patients and 17 uninfected patients)	Median 64 years (range 26-88); (61/44)	38	9	4	54	Patient-based
—	—	—	210 H pylori–positive images	315 control images (230 posteradication and 85 uninfected images)	—	161	70	49	245	Image-based
—	—	—	210 H pylori–positive images	85 uninfected images (H pylori–naïve)	—	161	9	49	76	Image-based (infected vs uninfected)
—	—	—	210 H pylori–positive images	230 posteradication images	—	161	61	49	169	Image-based (infected vs after-eradication)
—	—	—	85 uninfected images	230 posteradication images	—	76	61	9	169	Image-based (uninfected vs after-eradication)
Zheng et al [21], retrospective, China	CNNh	WLIi; histology with immunohistochemistry (if negative, urea breath test was done)	2575 H pylori–positive images	1180 control images (whether posteradication or uninfected images is unknown)	Mean 48.6 years (SD 12.9); (220/232)	2359	17	216	1163	Image-based
Shichijo et al [9], retrospective, Japan	CNN	WLI; serum or urine antibody, stool antigen, urea breath test	70 H pylori–positive patients	777 controls (284 posteradication and 493 uninfected images)	—	44	47	26	730	Patient-based
—	—	—	59 H pylori–positive images	477 uninfected images (H pylori–naïve)	—	44	12	15	465	Image-based (infected vs uninfected)
—	—	—	55 H pylori–positive images	182 posteradication images	—	44	35	11	147	Image-based (infected vs after-eradication)
—	—	—	481 uninfected images	249 posteradication images	—	465	102	16	147	Image-based (uninfected vs after-eradication)
Nakashima et al [23], prospective, Japan	CNN	WLI; serum antibody (H pylori IgG ≥10 U/mL was considered positive)	30 H pylori patients	30 controls (uninfected patients; H pylori–naïve)	—	20	12	10	18	Patient-based
—	—	LCI	—	—	—	29	1	1	29	Patient-based
—	—	BLIj-bright	—	—	—	29	4	1	26	Patient-based
Itoh et al [24], prospective, Japan	CNN	WLI; serum antibody (H pylori IgG ≥10 U/mL was considered positive)	15 H pylori–positive images	15 control images (uninfected patients; H pylori–naïve)	—	13	2	2	13	Image-based
Shichijo et al [22], retrospective, Japan	CNN	WLI; serum or urine antibody, stool antigen, urea breath test	72 H pylori patients	325 controls (uninfected patients; H pylori–naïve)	mean 50.4 (SD 11.2), (168/226)	64	41	8	284	Patient-based
Huang et al [25], retrospective, Taiwan	Sequential forward floating selection with SVMk	WLI; histology (3 pairs of samples from the topographic sites, including antrum, body, and cardia were obtained in a uniform way)	130 H pylori patients	106 controls (whether posteradication or uninfected patients is unknown)	—	128	21	2	85	Patient-based
Huang et al [26], prospective, Taiwan	Refined feature selection with neural network	WLI; histology (3 pairs of samples from the topographic sites, including antrum, body, and cardia were obtained in a uniform way)	41 H pylori patients	33 controls (whether posteradication or uninfected patients is unknown)	—	35	3	6	30	Patient-based

^aAI: artificial intelligence.

^bM/F: make/female.

^cTP: true positive.

^dFP: false positive.

^eFN: false negative.

^fTN: true negative.

^gLCI: linked color imaging.

^hCNN: convolutional neural network.

ⁱWLI: white-light imaging.

^jBLI: blue-laser imaging.

^kSVM: support vector machine.