The investigators will first perform a prospective comparison trial of 240 PPINR subjects at two centers over a 4 year period. Subjects will complete symptom questionnaires and undergo diagnostic testing (pH-impedance on PPI therapy, HRIM, 96-hthe wireless pH monitoring off of PPI therapy and mucosal impedance). Those who have a positive pH study and/or resume PPI therapy will receive escalation of acid suppression therapy with dexlansoprazole. Experiments 1a & 1b will compare the ability of 96-hthe wireless pH monitoring vs pH impedance to predict PPI requirement and response to dexlansoprazole, respectively. Experiment 1c will explore whether mucosal impedance is equivalent to 96-hthe wireless pH monitoring in predicting PPI requirement. Lastly, Experiment 1d will determine whether HRIM metrics can be utilized to determine reflux burden, mechanism and response to treatment. Next, the investigators will develop quality measures for reflux testing in order to develop a simplified management strategy for the PPINR group. The RAND/UCLA Appropriateness Methodology will be utilized with an expert working group to develop formal validated quality measures for reflux testing based on results from aim 1 in addition to the available literature & evidence. This will be conducted over twelve months (years 4 to 5).