The Reflux Symptom Score-12: Cross-cultural Adaptation and Validation for European Portuguese Speakers With Laryngopharyngeal Reflux

Abstract

ObjectivesTo translate and cross-culturally adapt the 12-item reflux symptom score (RSS-12) to European Portuguese (EP) and determine its clinimetric properties for symptomatic individuals with laryngopharyngeal reflux (LPR). Study designMultinational cross-sectional cohort study. MethodsThe English RSS-12 was cross-culturally adapted according to the recommendations of the international guidelines. The validation study included the completion of the RSS-12, reflux symptom index, and voice handicap index by symptomatic and asymptomatic subjects with LPR. The RSS-12 was completed a second time by symptomatic subjects. Nine clinimetric properties were analyzed according to the international guidelines for validation of patient-reported outcome measures. ResultsThe EP RSS-12 is equivalent to the English version (content, depth, and scoring). A total of 155 adults (84 with LPR symptoms) aged 21–78 years participated in the validation study. Statistical analyses revealed high internal consistency (Cronbach alpha >0.90), high test-retest reliability (intraclass correlation coefficient > 0.70, P < 0.001), low measurement error (Standard measure error of 5.21 for RSS and 1.59 for quality of life), good content validity (omission data <1% and item-total correlations > 0.652), good construct validity (61.9% of the total item variance with moderate item loadings), strong concurrent validity with reflux symptom index (rp = 0.772, P < 0.001) and moderate validity with voice handicap index (rp = 0.531, P < 0.001), and significantly known-groups validity (P < 0.001). The EP RSS-12 showed cross-cultural validity with French and Persian versions and high predictive validity with a cut-off value >8 for a sensitivity of 91.7% and a specificity of 91.5%. ConclusionsThe EP RSS-12 retained the features of the English version and is a reliable and valid patient-reported outcome measure for EP individuals with LPR in the study.