Diagnostic value of the proton pump inhibitor test for gastro-oesophageal reflux disease in primary care

Aim To assess the diagnostic accuracy of the proton pump inhibitor test in a primary care population as well as its additional value over reflux history, using the symptom association probability outcome during 24-h oesophageal pH recording as reference test for gastro-oesophageal reflux disease. Methods Subjects with symptoms suggestive of gastro-oesophageal reflux disease were recruited from primary care. After a 24-h pH recording with calculation of the symptom association probability, subjects started using 40 mg esomeprazole once daily for 13 days. The proton pump inhibitor test was considered positive when the subjects reported adequate symptom suppression. Data are presented as means with 95% confidence intervals. Results Successful 24-h pH recording was accomplished in 84 of the 90 subjects, while the symptom association probability was calculable in 74. The symptom association probability was positive in 70% of the subjects. The sensitivity of the proton pump inhibitor test was 0.91 (CI 0.78-0.96) and the specificity was 0.26 (CI 0.10-0.49). The mean likelihood ratio was 1.2 (CI 0.9-1.6) with little variation over the 13 consecutive proton pump inhibitor test days. The likelihood ratios of gastro-oesophageal reflux disease symptoms were comparable, ranging around 1. Conclusions In primary care patients with reflux symptoms gastro-oesophageal reflux disease is highly prevalent. Under these conditions the additional value of short-term treatment with a proton pump inhibitor for diagnosing gastro-oesophageal reflux disease is limited.