370 Can Subjective GERD Questionnaires Predict Abnormal Findings in pH Impedance Testing?

Abstract

INTRODUCTION: Subjective and objective tools are used to diagnose GERD, including questionnaires and 24 hour pH impedance. We examined correlations between the GERD questionnaire (GERDQ) and Reflux Symptom Index (RSI) questionnaires against component metrics of 24-hour pH impedance testing (number of reflux events, esophageal acid exposure, and symptom association). METHODS: 117 consecutive adult patients referred for PPI refractory GERD symptoms were included. All patients completed GERDQ and RSI, which are validated questionnaires for predicting GERD based on typical and atypical reflux symptoms, respectively. Patients then underwent 24 hour pH impedance testing. RSI score, GERDQ grade, pH impedance results (positive, negative), esophageal acid exposure (EAE), number of reflux events, and symptom association were variables of interest analyzed using Chi-square tests. RESULTS: A positive GERDQ result (grade C or D) was not significantly associated with abnormal pH impedance (P = 0.08). There was no correlation between positive GERDQ and abnormal EAE (P = 0.79) or number of reflux events (P = 0.26). However, positive symptom association was associated with an abnormal GERDQ (P = 0.01). Similarly, there was no significant correlation between positive RSI and abnormal pH-Imp (P = 0.06), abnormal EAE (P = 0.19), or number of reflux events (P = 0.09). Positive RSI was significantly associated with positive symptom association (P = 0.04). 58% (52/90) of patients with positive GERDQ also had positive RSI (P = 0.001). CONCLUSION: Our data suggest that positive subjective GERD assessment tools (GERDQ and RSI) are associated with positive symptom association component of pH impedance testing. However abnormal acid exposure or number of reflux episodes are more difficult to predict. Many patients report typical and atypical GERD symptoms, suggesting an overlap of symptoms. This may be exaggerated by self-report bias, and is not predictive of pH-impedance result.