The proton pump inhibitor test for gastroesophageal reflux disease: optimal cut-off value and duration

There is no accepted gold standard for the diagnosis of gastroesophageal reflux disease (GERD).

To assess the optimal cut-off value and duration of the proton pump inhibitor (PPI) test in GERD patients with and without oesophagitis.

Prospective study of 544 patients undergoing upper GI endoscopy and treated for 2 weeks with PPIs at double dose, and for 3 additional months at standard dose. The status of the patient at end of treatment was used as an independent diagnostic standard, i.e. patients completely asymptomatic were considered as "true" GERD patients.

PPI test was positive in 89.7-97.8% of the patients according to the cut-off or duration of test used. Test sensitivity ranged from 95.5% to 98.8%, whereas specificity did not exceed 36.3%. Positive predictive values ranged from 87% to 80%, negative predictive values ranged from 58% to 70%, respectively.

The PPI test is a sensitive but poorly specific test in GERD patients. Its optimal duration is 1 week, and the optimal cut-off value is a decrease of heartburn score ≥75%. The diagnostic yield is higher in erosive oesophagitis compared with non-erosive reflux disease patients, similarly to the symptomatic response to 3-month PPI therapy.