Association between reflux and symptoms during ambulatory reflux monitoring: pros and cons of existing methods.

Ambulatory reflux monitoring provides information on the quantity of gastroesophageal reflux and, if symptoms are registered during the study, provides insights into the relation between symptoms and reflux. Several symptom-reflux association analysis indices have been developed to express the relationship between onset of symptom and reflux in a numerical way. One of these indices is the binomial symptom index, introduced by Ghillebert et al. in 1990. The binomial symptom index can be used to study the relationship between symptoms and acid reflux. In this issue of Neurogastroenterology and Motility Barriga-Rivera et al. describe the use of Monte Carlo simulations to investigate the effect of random changes in reflux rates and symptom occurrences on binomial symptom index outcome. Their analysis shows that this index can be used to measure the strength of reflux symptom association. Performing symptom-reflux association analysis is important as the outcome has been shown to be reproducible and can be used as a predictor to response to acid-suppressive treatment. Despite some limitations, use of symptom-reflux association analysis is a valuable clinical tool that can provide unique insights into the cause of a patient's symptoms.