Thresholds of gastroesophageal reflux for diagnosis of esophageal reflux diseases

Table 1 Anamnestic data and endoscopic findings

Parameter	Gastroesophageal reflux patients with esophagitis (n = 228)	Gastroesophageal reflux patients without esophagitis (n = 172)	Healthy controls (n = 100)
Age, yr	52 ± 18.3	46 ± 7.5	48 ± 9.4
Sex, male/female	158/70	122/50	60/40
Duration, yr	12.4 ± 3.2	8.1 ± 3.8
GER symptoms, %	100	100	0
Smoker, %	54.3	44.2	35
Alcohol consumer, %	25	20.3	22
Hiatal hernia, %	18.4	11.0	2.0
Grade of esophagitis, %
I - II	72.3	0	0
III - IV	27.7	0	0

Table 2 Reflux episodes and pH fluctuations in gastroesophageal reflux patients (¯x ± s)

Group	pH fluctuations			Reflux episodes
	n	Duration, min	Time, % 24 h	n	Duration, min	Time, % 24 h
Gastroesophageal reflux patients with
Esophagitis
Total	67 ± 46	191.7 ± 118.9	12.7 ± 6.5b	22 ± 31	45.4 ± 110.6	3.1 ± 7.5b
Day	55 ± 34	124.0 ± 97.5	8.2 ± 4.6b	15 ± 13	19.1 ± 58.7	1.3 ± 2.7b
Night	12 ± 8	50.1 ± 35.4	3.3 ± 4.5b	7 ± 10	22.8 ± 64.7	1.5 ± 4.8b
GER patients without
Esophagitis
Total	50 ± 18	130.4 ± 57.5	9.5 ± 2.8b	14 ± 14	27.4 ± 68.3	2.0 ± 5.0b
Day	41 ± 14	94.0 ± 35.7	6.8 ± 3.5b	11 ± 7	18.8 ± 45.2	1.4 ± 12.9b
Night	9 ± 8	36.3 ± 26.4	2.6 ± 3.1b	3 ± 6	8.6 ± 24.7	0.6 ± 2.2b
Healthy controls
Total	23 ± 16	41.3 ± 30.7	2.7 ± 2.0	3 ± 3	3.0 ± 5.7	0.2 ± 0.4
Day	20 ± 11	37.3 ± 24.1	2.5 ± 1.9	2 ± 2	2.0 ± 2.4	0.1 ± 0.2
Night	3 ± 5	4.1 ± 3.9	0.3 ± 0.4	1 ± 1	1.0 ± 2.1	0.1 ± 0.1

^bP < 0.01 vs healthy controls.

Table 3 Correlations between the percentages of the time with pH fluctuations/reflux episodes and the total duration and numbers of episodes

Group	Total duration		Total number
	r	P	r	P
Gastroesophageal reflux patients with esophagitis
Time (%) with pH fluctuations	0.92	< 0.01	0.53	< 0.01
Time (%) with reflux episodes	0.67	< 0.01	0.65	< 0.01
GER patients without esophagitis
Time (%) with pH fluctuations	0.88	< 0.01	0.29	> 0.05
Time (%) with reflux episodes	0.42	< 0.05	0.45	< 0.01
Controls
Time (%) with pH fluctuations	0.98	< 0.01	0.82	< 0.01
Time (%) with reflux episodes	0.62	< 0.01	0.46	< 0.05

^*Total duration: duration of pH fluctuations + duration of reflux episodes; Total numbers: numbers of pH fluctuations + numbers of reflux episodes.

Table 4 Sensitivity and specificity of pH fluctuations and reflux episodes for the diagnosis of abnormal gastroesophageal reflux

Threshold, %		Sensitivity, %
		gastroesophageal reflux patients with esophagitis	gastroesophageal reflux patients without esophagitis
pH fluctuations	< 6.7	93.7	93.3
Reflux episodes	< 0.1	96.7	90.0
Combination		96.7	90.0

^*Combination: pH fluctuation < 6.7% + reflux episode < 0.1%.