Symptomatic correlation variables in patients with pathological gastroesophageal reflux disease

INTRODUCTION. There are three indexes that correlate symptoms and reflux episodes in pHmetry tests. The utility of these indexes have been evaluated in prospective trials but their advantages and disadvantages remain controversial. To assess the clinical utility of the pHmetric symptomatic correlation indexes in patients with pathological acid reflux. A sequential pilot study of pHmetry tests was performed between September 2008 and June 2010. Twenty patients with gastroesophageal reflux and a DeMeester score above 14.5 were included. For the analysis, a distinction was made between strong acid reflux episodes (pH < 4) and weak acid reflux episodes (pH < 7 and > 4). The following indexes were calculated for both groups mentioned before: symptom index (SI), symptom sensitivity index (SSI) and symptom association probability (SAP). The mean age was 54 and 55% of patients were male. There were 116 symptomatic episodes (mean 5.8 per patient), 1,634 strong acid reflux episodes and 555 weak acid reflux episodes. Twelve (60%) had positive SI for strong acid reflux. Twelve had positive SSI for strong acid reflux and 91.66% of them had positive SI. Only 4 patients had a positive SAP. Only 2 patients had a positive SI for weak acid reflux and none of them had either a positive SI for strong acid reflux or a positive SAP for weak acid reflux. Finally, 30% of patients had a positive SSI for weak acid reflux. Positive correlation was significantly higher in strong acid rather than in weak acid reflux. SAP was the index with the lowest percentage of positivity. On the other hand, there was a high concordance between SI and SSI. Thus, the PAS index does not seem to have enough clinical utility in this cohort of patients.