Prevalence of gastroesophagopharyngeal acid reflux events: an evidence-based systematic review

The prevalence of GEPR in controls and patients with RL varies in the studied 4 areas above the UES. The percentage of the subjects with GEPR increased as the probe was located more closely to the UES. Differences in demographic characteristics of the subjects, interventions used to select subjects, and pharyngeal pH monitoring techniques were identified as factors possibly contributing to inconsistent pharyngeal pH monitoring findings. The documented differences in methodology of existing studies make comparison of the studies difficult.