Validation of the Reflux Symptom Index in French-Speaking Quebec Patients

ImportanceThere is a need to culturally adapt this commonly used patient-reported outcome measure, the Reflux Symptom Index (RSI), for use in Canada and Quebec's French population.ObjectiveTo translate and validate the RSI for use in Quebec French speakers, ensuring reliability and validity within this population.DesignProspective case-control study.SettingVoice and Dysphagia Laboratory at the McGill University Health Centre in Montreal, Quebec, Canada.ParticipantsPatients with laryngopharyngeal reflux (LPR) and healthy controls were recruited during outpatient clinical laryngology visits. Participants were eligible if they were at least 18 years old and spoke French as their native language.Intervention or ExposuresA Quebec-French version of the RSI (Q-Fr-RSI) was validated using the "translation-back-translation" method. Participants completed the Q-Fr-RSI, Fr-VHI, and their laryngoscopy was examined and assigned a Reflux Finding Score at their initial visit. Participants repeated the Q-Fr-RSI via telephone follow-up.Main Outcome MeasuresFeasibility, internal consistency, test-retest reliability, and construct validity of the Q-Fr-RSI were assessed.ResultsEighty-nine participants were recruited: 49 patients within the experimental group and 40 subjects within the control group. The feasibility was evaluated as percentage of missing answers in the full sample at the first time point, 0%, and second time point, 1.2%. Internal consistency via Cronbach's alpha was high (.90). Intra-rater reliability via intraclass correlation demonstrated good level of agreement (.84). Internal validity demonstrated a strongly significant difference between the groups' answers (mean score of 23.9 vs 6.65, respectively, P < .001).ConclusionsThis data suggest that the Q-Fr-RSI can be used to assess LPR in the French-speaking Canadian population.RelevanceIn the bilingual country of Canada, and especially in the province of Quebec where over 90% of people speak French, an appropriate validation of the Q-Fr-RSI allows all patients to be monitored adequately. A Quebec-French patient-reported outcome measure can accurately represent these patients in future research studies utilizing these metrics.