Diagnostic Accuracy of the Proton Pump Inhibitor Test in Gastroesophageal Reflux Disease and Noncardiac Chest Pain

Background: Response to a trial of proton pump inhibitors (PPIs) is currently accepted as a first step in the management of gastroesophageal reflux disease (GERD). However, information on the diagnostic performance of the PPI test is limited. Aim: The aim of this study was to determine the diagnostic accuracy of the PPI test in GERD and noncardiac chest pain (NCCP) and to assess the test performance in erosive reflux disease (ERD) and nonerosive reflux disease (NERD). Methods: Web of Science, Cochrane Controlled Register of Trials (CENTRAL), and MEDLINE were searched for studies reporting the diagnostic accuracy of the PPI test in adult patients with typical GERD and NCCP who underwent evaluation using an accepted reference standard, from January 1, 1950, through February 1, 2021. Subgroup analyses were performed, and the risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Results: Nineteen studies (GERD=11, NCCP=8) involving 1691 patients were included. In GERD, the PPI test had 79% pooled sensitivity [95% confidence interval (CI), 72%-84%], and 45% pooled specificity (95% CI, 40%-49%). In NCCP, pooled sensitivity and specificity were 79% (95% CI, 69%-86%) and 79% (95% CI, 69%-86%), respectively. In ERD, the PPI test had 76% pooled sensitivity (95% CI, 66%-84%) and 30% pooled specificity (95% CI, 8%-67%). In NERD, the PPI test had 79% pooled sensitivity (95% CI, 70%-86%) and 50% pooled specificity (95% CI, 39%-61%). Conclusions: The PPI test was sensitive in GERD but with suboptimal specificity. The test performed better in GERD-related NCCP. Diagnostic accuracy was comparable in ERD and NERD.