Introduction 24 hour pH-impedance reflux monitoring is considered the gold standard in diagnosing pathological gastroesophageal reflux (GOR). Alternative method is catheter-free Bravo capsules (96 hours). To date, their cost-effectiveness has yet to be compared. At Guy’s Hospital, London, UK, the cost of Bravo is estimated to be £1,200 (including endoscopy) and pH-impedance to be £800 (including high resolution manometry). It is generally assumed that the higher cost of Bravo monitoring is justifiable as it is thought to have a higher diagnostic yield due to better patient compliance and a longer monitoring time.

Methods Patients who had a Bravo or pH-impedance study during May-November 2015 were selected. The more cost-effective method was defined as the technique with lower cost (including cost of non-diagnostic results) per diagnostic procedure. To identify non-diagnostic results, the patients with pathological GOR, patients with positive symptom-reflux associations, patients with supragastric belching and patients who were adequately symptomatic (therefore having negative symptom-reflux association) were removed. Positive symptom-reflux association was considered as symptom association probability (SAP) ≥95% and/or symptom index (SI) ≥50%.

Results 81 Bravo patients and 145 pH-impedance patients were analysed. 50 (61.7%) Bravo patients and 69 (47.5%) pH-impedance patients were diagnosed with pathological GOR, 14 (17.3%) Bravo and 44 (30.3%) pH-impedance patients had hypersensitive oesophagus, 3 (2.1%) pH-impedance were patients diagnosed with supragastric belching causing symptoms, and 10 (12.3%) Bravo and 14 (9.7%) pH-impedance patients experienced symptoms unexplained by reflux events (negative symptom-reflux association). The remaining 7 (8.6%) Bravo and 15 (10.3%) pH-impedance entries therefore represent the proportion of non-diagnostic investigations. Cost calculations revealed that each Bravo with diagnostic yield costs £1313.5 whilst each pH-impedance with diagnostic yield costs £892.3 (Table 1). This means that for each diagnosis made by Bravo there is an additional cost of £421.2.

Conclusion The cost-effectiveness of pH-impedance reflux monitoring seems to be superior to Bravo system to make a reflux-related diagnosis. However, this study does not take into account other advantages of each method in clinical use.

Disclosure of Interest None Declared