Nora Šiupšinskienė, Kęstutis Adamonis, Peter Belafsky, Asta Aukštakalnienė, Sigutė Norkienė


The aim of the study was to develop the Lithuanian version of Reflux symptom index (RSI) questionnaire and to assess psychometric characteristics of the RSI in patients with Laryngopharyngeal reflux (LPR). The Lithuanian version of RSI was composed according to standard methodology and included forward and back translations (English-Lithuanian-English) of the original questionnaire, comparison of original and two back-translations using Pearson correlation coefficient (r) in the United States (USA), committee review and psychometric testing of the final version in Lithuania. Four groups of adult persons were investigated. USA group consisted of thirty voice patients, Lithuanian pilot study group – of 20 patients with erosive esophagitis, LPR group- of 25 patients (diagnosis was proven by erosive or histological esophagitis on esophagoscopy), and control group- of 27 vocally healthy persons. High correlation was found between original and two back-translated RSI versions in the USA group (r=0.99-0.98, p<0.0001). The internal consistency of the final version of Lithuanian RSI was reliable with Cronbach‘s alpha=0.87. The test-retest analysis also showed high correlation between two pre-treatment testings (r=0.99) equally for LPR and control groups. The mean RSI was significantly higher for LPR group than control group: 18.2±7.1 and 3.8±4.4, respectively (p<0.0001). Pathological RSI (³13) and pathological reflux finding score (³7) were similarly found in 88.0% and in 84.0% of LPR patients. The most sensitive and specific limiting value for discrimination between patients and controls according to ROC curve was RSI > 10 points (overall classification accuracy 92.3%). In conclusion, the Lithuanian version of RSI questionnaire is reliable and valid instrument and can be used in the diagnosing of LPR patients.

Keyword(s): reflux symptom score; liguistic adaptation; reliability; validity.
DOI: 10.5200/sm-hs.2015.119
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