“…[5][6][7][8] The number of reflux events at on-therapy impedance-pH monitoring is directly related to AET at off-therapy pH testing, 7 but few studies have documented the clinical utility of this parameter in PPI-refractory patients evaluated during ongoing therapy. 8,10,11,19 Despite their well-recognized limitations, symptom-reflux association indexes are considered worthwhile for the clinical evaluation of patients with suspected reflux disease 24 : however, their positivity is directly related to high reflux rates, 9 only a minority of reflux events are associated with symptoms, 25 Despite the efficacy of laparoscopic fundoplication, 26,27 side effects have limited its utilization 28 : therefore, a firm diagnosis of PPI-refractory GERD is warranted before advising surgery. 2,4 Our results suggest that low values of PSPW index in PPI-refractory heartburn patients studied with on-therapy impedance-pH monitoring can increase our confidence in distinguishing PPI-refractory GERD from FH and in advising antireflux interventions.…”