Patel D, Harb A, Vaezi M. Curr Gastroenterol Rep. 2016 Mar;18(3):12.

The prevalence of gastroesophageal reflux disease (GERD) has been increasing since the 1990 s, with up to 27.8 % of people in North America affected by this disorder. The healthcare burden of patients who primarily have extra-esophageal manifestations of GERD (atypical GERD) is estimated to be 5 times that of patients with primarily heartburn and regurgitation due to lack of a gold standard diagnostic test, poor responsiveness to PPI therapy, and delay in recognition. Empiric twice daily PPI therapy for 1-2 months is currently considered the best diagnostic test, but due to poor responsiveness to PPIs in patients with atypical GERD in multiple randomized controlled trials, newer modes of diagnostic procedures such as oropharyngeal pH monitoring have gained significantly more traction. The utility of oropharyngeal pH monitoring systems such as Restech Dx-pH is currently limited due to lack of consensus on normal and abnormal cutoff values. Recent studies suggest its utility as a prognostic tool and its ability to predict responsiveness to medical and surgical therapy. However, routine use of oropharyngeal pH monitoring is still not widespread due to the lack of well-controlled prospective studies.