A comparison of rating scales and measures used in the diagnosis of extraesophageal reflux

Abstract

Extraesophageal Reflux (EER) is the backflow of stomach contents into the larynx. The current “gold standard” for diagnosis is 24-hour pH probe monitoring. Traditional pH analysis is performed using a criterion of pH 4. The Reflux Area Index (RAI) is a “time-corrected” composite score representing the frequency, duration, and pH acidity of EER events that occur during testing. Additional diagnostic tools such as the Reflux Symptom Index (RSI) and Reflux Finding Score (RFS) provide supplementary information pertaining to EER diagnosis. The RSI is a 9-item patient scale that assesses symptoms of EER, while the RFS is an 8-item clinical severity scale that assesses laryngeal physical findings of EER. The present investigation was designed to evaluate the level of agreement between RAI scores on pH probe monitoring, the RSI, and the RFS. Inter- and intra-rater reliability of the RFS was assessed. Furthermore, a new criterion of pH 5 was also employed to evaluate its effects on agreement. Finally, participants provided information about the 24-hour testing period as it pertains to how typical their experiences were, and how compliant they were to testing protocol.

Eighty-two (72 patients and 10 controls) adult participants were enrolled in this prospective study. Participants completed the RSI, RFS, 24-pH probe monitoring, and a post-evaluation questionnaire. Results of this study revealed poor agreement between the diagnostic tools, regardless of which pH criterion was used. Inter-rater reliability of the RFS was “fair,” while intra-rater reliability was “moderate.” The RFS and RAI scores failed to identify patients from normal controls. Participants reported adherence to typical daily routines and a high level of compliance during the test period. Possible explanations for the discordance between test instruments are discussed.