Development and validation of a laryngopharyngeal reflux questionnaire, the Pharyngeal Reflux Symptom Questionnaire

Abstract

Objective. To develop and validate the Pharyngeal Reflux Symptom Questionnaire (PRSQ), a comprehensive, disease-specific, self-administered questionnaire for laryngopharyngeal reflux (LPR) disease. Material and methods. The PRSQ was developed based on empirical evidence from a literature review and expert input from physicians and patients and tested in a pilot study. In this validation study, a total of 228 patients were included and classified according to the Reflux Symptom Index (RSI) cut-off score. Patients with an RSI score > 13 were defined as abnormal, i.e. having LPR disease (n = 102), and those with a score between 0 and 13 were defined as normal controls (n = 126). Psychometric properties of the PRSQ were evaluated by exploring the factor structure and by evaluating internal consistency and item convergent and discriminant validity. Convergent and discriminant validity were determined by using the Laryngopharyngeal Reflux–Health Related Quality of Life questionnaire (LPR-HRQL), the RSI and the Short Form-36. Results. The PRSQ was well accepted by the patients. Compliance was satisfactory and missing item rates were low. After item reduction, due to items not being conceptually relevant or scaling errors and/or low factor loadings, a construct was achieved with no scaling errors and high internal consistency (Cronbach's alpha 0.79–0.93). The correlations between the PRSQ and similar dimensions in the RSI and LPR-HRQL were generally strong. Discriminant validity was satisfactory as the questionnaire discriminated between patients with and without LPR disease. Conclusion. The PRSQ showed good psychometric properties and may become a valuable instrument for assessing LPR disease.

Key Words::

• Laryngopharyngeal reflux
• questionnaire
• validation

Acknowledgements

We are indebted to Ann Christin Mjörnheim, RN, for technical assistance with the questionnaires and to Gunnar Ekeroth for statistical assistance. This study was supported by the Assar Gabrielsson Foundation, the Research and Development Council, Västra Götaland (Sweden) County, the Medical Faculty of Göteborg University and Astra Zeneca R&D, Mölndal, Sweden.