Normal values and regional differences in oesophageal impedance-pH metrics: a consensus analysis of impedance-pH studies from around the world

Limitations of existing impedance-pH thresholds include small sample size of normative studies, inclusion of artefactual pH drops and incorrect identification of impedance reflux events. We aimed to obtain new impedance-pH thresholds from expert consensus analysis of tracings from a large number of healthy subjects.Of 541 studies performed worldwide using two different systems (Diversatek, USA, and Laborie, Netherlands), 150 tracings with...