Objective: To assess the need for pH testing in diagnosing laryngopharyngeal reflux (LPR).
Study design: Case series with planned data collection.
Setting: Tertiary care center.
Subjects and methods: On the basis of symptoms and/or abnormal endoscopic findings, more than 500 patients underwent 24-hour pharyngeal pH testing at a single center (using the Dx-pH probe) between January 2009 and June 2011. A total of 163 patients not on proton-pump inhibitors at the time of study and with complete data available for analysis (pH results, body mass index, smoking status, pretest reflux symptom index) were divided into 2 groups by positive (n = 70) and negative (n = 93) Ryan Score. The Reflux Symptom Index (RSI) was compared between groups and assessed overall against Ryan Score parameters at different pH thresholds. The diagnostic utility of an RSI ≥ 13 for prediction of Ryan Score was assessed.
Results: No significant difference in RSI was seen between Ryan-positive (17.50 ± 11.47) and Ryan-negative (14.95 ± 11.43) patients (P = .161). Overall, RSI correlated poorly with percentage time spent below pH thresholds 6.5, 6.0, 5.5, and 5.0 and upright and supine Ryan parameters at these thresholds (as determined by linear regression analysis). The sensitivity, specificity, positive predictive value, and negative predictive value of RSI ≥ 13 for Ryan positivity were 55.7%, 47.3%, 44.3%, and 58.7%, respectively.
Conclusion: Our findings show that in our population of otolaryngology patients, the diagnosis of LPR cannot be reliably made on the basis of symptoms alone. Diagnosis, and in particular treatment decisions, should ideally be made on the basis of a combination of symptoms, signs, and confirmatory testing.