Comparison of multichannel intraluminal impedance-pH monitoring and reflux scintigraphy in pediatric patients with suspected gastroesophageal reflux

Table 1 Comparison of pH monitoring and gastroesophageal reflux scintigraphy

	Gastroesophageal scintigraphy positive	Gastroesophageal scintigraphy negative	Total
pH monitoring positive	25	9	34
pH monitoring negative	22	4	26
Total	47	13	60

Kappa value= -0.118 [P = 0.302, 95%CI: -0.232-(-0.004)]; Overall percent agreement = 48.3%; When pH monitoring is considered as reference test, positive percent agreement = 73.5% and negative percent agreement = 15.4%.

Table 2 Comparison of multichannel intraluminal impedance monitoring and gastroesophageal reflux scintigraphy

	Gastroesophageal scintigraphy positive	Gastroesophageal scintigraphy negative	Total
MII monitoring positive	34	10	44
MII monitoring negative	13	3	16
Total	47	13	60

Kappa value = -0.042 (P = 0.741, 95%CI: -0.17-0.086); Overall percent agreement = 61.7%; When MII monitoring is considered as a reference test, positive percent agreement = 77.3% and negative percent agreement = 18.8%. MII: Multichannel intraluminal impedance.

Table 3 Comparison of multichannel intraluminal impedance/pH monitoring and gastroesophageal reflux scintigraphy

	Gastroesophageal scintigraphy positive	Gastroesophageal scintigraphy negative	Total
MII-pHM positive	41	10	51
MII-pHM negative	6	3	9
Total	47	13	60

Kappa value 0.116 (P = 0.357, 95%CI: -0.01-0.24); Overall percent agreement = 73.3%; When MII-pHM is considered as reference test, positive percent agreement = 80.4% and negative percent agreement = 33.3%. MII-pHM: Multichannel intraluminal impedance-pH monitoring.

Table 4 Comparison of multichannel intraluminal impedance and pH monitoring

	pH monitoring positive	pH monitoring negative	Total
MII monitoring positive	27	17	44
MII monitoring negative	7	9	16
Total	34	26	60

Kappa = 0.147 (P = 0.223, 95%CI: 0.026-0.268). Overall percent agreement = 60%; MII: Multichannel intraluminal impedance.

Table 5 Sensitivity, specificity, positive and negative predictive values of diagnostic tests according to assumed gold standard test

Test	Gold standard
	MII-pH monitoring				GES
	Sensitivity, %	Specificity, %	PPV, %	NPV, %	Sensitivity, %	Specificity, %	PPV, %	NPV, %
	(95%CI)	(95%CI)	(95%CI)	(95%CI)	(95%CI)	(95%CI)	(95%CI)	(95%CI)
MII-pHM	-	-	-	-	87.2	23.1	80.4	33.3
					(73.6-94.7)	(6.2-54.0)	(66.5-89.7)	(9.0-69.1)
pHM alone	66.7	100	100	34.6	53.2	30.8	73.5	15.4
	(52.0-78.9)	(62.9-100.0)	(87.4-100.0)	(17.9-55.6)	(38.2-67.6)	(10.4-61.1)	(55.3-86.5)	(5.0-35.7)
MII alone	73.3	100	100	56.3	72.3	23.1	77.3	18.6
	(73.1-93.8)	(62.9-100.0)	(90.0-100.0)	(30.6-79.2)	(57.1-83.9)	(6.0-54.0)	(61.8-88.0)	(5.0-46.3)
GES	80.4	33.3	87.2	23.1	-	-	-	-
	(66.5-89.7)	(9.0-69.1)	(73.6-94.7)	(6.1-54.0)

GES: Gastroesophageal scintigraphy; MII-pHM: Multichannel intraluminal impedance-pH monitoring; pHM: Esophageal pH monitoring; MII: Multichannel intraluminal impedance monitoring; PPV: Positive predictive value; NPV: Negative predictive value.