Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases: A prospective, blind clinical study

Table 1 Methods for detecting diseases in experimental and control groups

		EGD
		Positive	Negative	Total
ds-MCE	Positive	a	b	a + b (R1)
	Negative	c	d	c + d (R2)
	Total	a + c (C1)	b + d (C2)	a + b + c + d (N)

(1) Sensitivity = Number of true positives/(number of true positives + number of false negatives) × 100 = a/C1; (2) Specificity = number of true negatives/(number of true negatives + number of false positives) × 100 = d/C2; (3) Positive predictive value = number of true positives/(number of true positives + number of false positives) × 100 = a/R1; (4) Negative predictive value = number of true negatives/(number of true negatives + number of false negatives) × 100 = d/R2; And (5) Diagnostic accuracy (concordance) = (number of true positives + number of true negatives)/total number × 100 = (a + d)/ N. Based on the definitions, two-sided 95%CI were calculated for each of the above indicators. EGD: Esophagogastroduodenoscopy; ds-MCE: Detachable string magnetically controlled capsule endoscopy.

Table 2 Demographic and baseline characteristics

	Subjects (n = 50)
Sex, % (n)
Male	54% (27/50)
Female	46% (23/50)
Age (yr)
n	50
Mean	53.26
Median	56
Min, Max	22, 73
Height (cm)
n	50
Mean	164.3
Median	162
Min, Max	150.0, 182.0
Weight (kg)
n	50
Mean	63.76
Median	63.5
Min, Max	42, 93
BMI (kg/m2)
n	50
Mean	23.5
Median	23.34
Min, Max	16.41, 31.25
Medical history
Esophagitis	48
Barrett's esophagus	1
Esophageal hiatal hernia	2
Superficial gastritis	8
Atrophic gastritis	2

EGD: Esophagogastroduodenoscopy; ds-MCE: Detachable string magnetically controlled capsule endoscopy; BMI: Body mass index.

Table 3 Detection of esophageal lesions by esophagogastroduodenoscopy and detachable string magnetically controlled capsule endoscopy

		EGD
		Positive	Negative	Total
ds-MCE	Positive	18	4	22
	Negative	3	25	28
	Total	21	29	50

EGD: Esophagogastroduodenoscopy; ds-MCE: Detachable string magnetically controlled capsule endoscopy.

Table 4 Detection of esophageal lesions by esophagogastroduodenoscopy and detachable string magnetically controlled capsule endoscopy

Primary endpoint	95%CI
Sensitivity	85.71% (62.64%, 96.24%)
Specificity	86.21% (67.43%, 95.49%)
Positive predictive value	81.82% (58.99%,94.01%)
Negative predictive value	89.29% (70.63%, 97.19%)
Diagnostic accuracy	86% (72.64%,93.72%)

Table 5 Perception analysis of subjects undergoing esophagogastroduodenoscopy and detachable string magnetically controlled capsule endoscopy examination

Projects	EGD (n = 49)	ds-MCE (n = 50)
Comfort level
0 Very comfort	6	13
1 Comfort	13	27
2 Tolerable	23	10
3 Uncomfortable	3	0
4 Very uncomfortable	4	0
P value (Kruskal-Wallis test)	< 0.0001
Pain during the examination
0 No	23	40
1 A little	18	9
2 Mild	7	1
3 Serious	1	0
4 Unbearable	0	0
P value (Kruskal-Wallis test)	0.0004
Discomfort during the examination
0 No	14	31
1 A little	21	14
2 Mild	6	5
3 Serious	7	0
4 Unbearable	0	0
P value (Kruskal-Wallis test)	0.0003
Pain after the examination
0 No	29	44
1 A little	15	6
2 Mild	5	0
3 Serious	0	0
4 Unbearable	0	0
P value (Kruskal-Wallis test)	0.0008
Discomfort after the examination
0 No	23	42
1 A little	18	7
2 Mild	7	1
3 Serious	1	0
4 Unbearable	0	0
P value (Kruskal-Wallis test)	< 0.0001
Convenience of inspection
0 Very convenient	14	25
1 Convenient	29	25
2 Inconvenient	5	0
3 Very inconvenient	1	0
P value (Kruskal-Wallis test)	0.0074

EGD: Esophagogastroduodenoscopy; ds-MCE: Detachable string magnetically controlled capsule endoscopy.