Table 1.

Normal thresholds of ambulatory pH-testing (according to [9])

Component	Mean and S.D. Group I Control	p-value	Normal value	% Incidence Group II Abnormal
Supine period	0.286% ± 0.467	0.001	<1.2%	81.5% (31/38)
Total period	1.478% ± 1.381	0.001	<4.2%	79% (30/38)
# Episodes >5 min	0.6 ± 1.241	0.001	3 or less	73.6% (28/38)
Longest episode	3.866 min ± 2.689	0.001	<9.2 min	73.6% (28/38)
Upright period	2.33% ± 1.975	0.01	<6.3%	63.1% (24/38)
# Total episodes	20.6 ± 14.773	0.01	<50	50% (19/38)