Time esophageal pH < 4 overestimates the prevalence of pathologic esophageal reflux in subjects with gastroesophageal reflux disease treated with proton pump inhibitors

Table 3 Parameter Values for the Relationship Between Measures of Gastric Acidity and the Odds Pathologic Esophageal Reflux.

	Index Study (n = 46 records)		3rd Study (n = 156 records)
Period	Integrated Acid (mmol.hr/L)	Time pH < 4 (%)	Integrated Acid (mmol.hr/L)	Time pH < 4 (%)
24-hour (900–900)
ROC Area	0.77 (0.59, 0.94)	0.68 (0.52, 0.83)	0.74 (0.66, 0.82)	0.64 (0.55, 0.74)
Overall Odds Pathologic Reflux	0.18	0.77	0.37	2.52
Postprandial (900–2200)
ROC Area	0.71 (0.55, 0.88)	0.69 (0.52, 0.85)	0.80 (0.74, 0.87)	0.77 (0.70, 0.85)
Overall Odds Pathologic Reflux	0.44	0.48	1.05	1.31
Nocturnal (2200–900)
ROC Area	0.75 (0.57, 0.93)	0.62 (0.45, 0.78)	0.75 (0.67, 0.83)	0.62 (0.53, 0.71)
Overall Odds Pathologic Reflux	0.18	0.84	0.21	1.59

Parameter values were calculated from data illustrated in Figures 1–4 using values for gastric acidity stratified on the basis of pathologic esophageal acidity. Numbers in parentheses for ROC area give the 95% confidence interval.

ISSN: 1471-230X