Oesophageal pH monitoring is of limited value in the diagnosis of "reflux-cough".

Reflux-cough is a diagnosis based on demonstrating both gastro-oesophageal reflux and a positive response to anti-reflux therapy. The authors sought to determine early and long-term response to therapy in patients with a "positive" 24 h oesophageal pH study, and identify any features which might predict response. Patients with chronic cough were recruited from July 1998 to July 2002. Those with a positive pH study were given dietary advice and an 8-week trial of omeprazole (20 mg b.i.d.). Response was judged after 8 weeks (clinical follow-up), and at long-term follow-up (telephone questionnaire). A total of 146 patients underwent pH monitoring with 82 (56.2%) "positive" studies. Follow-up data was available in 60 patients, with 49 receiving anti-reflux therapy, of which 20 (40.8%) reported a positive treatment response. At long-term follow-up (median 30 months), there was a significantly lower response (14 out of 49, 28.5%), with no significant difference in either acid exposure times (distal/proximal) or symptom correlation between responders and nonresponders at early or long-term follow-up. In conclusion, despite "positive" pH studies, over half of the patients (55.1%) failed to respond to therapy. No features on pH monitoring accurately predicted response. Short-term response did not predict long-term response. The precise role for pH monitoring in the assessment of chronic cough remains to be defined.