Reliability and Validity of the Turkish Reflux Symptom Index

Objective. To validate and assess reliability of the Turkish Reflux Symptom Index (T-RSI). Study Design. Cross-sectional case-control study. Materials and Methods. A Turkish version of the original American English RSI was developed. One hundred thirty-two patients with a Reflux Finding Score (RFS) > 7, and 162 healthy controls (HC) with RFS <= 7 were included in the study. To assess reliability, the T-RSI was scored twice, within a 7-14 day window. For construct validity, the scores obtained in the study group were compared to the scores from the HC group. A correlation between RSI and RFS was assessed to determine content validity. Finally, sensitivity and specificity of the index was calculated using a receiver operating characteristic curve analysis. Results. The T-RSI showed excellent internal consistency (Cronbach's alpha = 0.912). Item-total correlation coefficients ranged between 0.572 and 0.773. The Pearson product-moment correlation test indicated that the T-RSI is a reliable tool (r = 0.931, n = 107, P < 0.001). There were significant difference between the study group and the HC group for the mean RSI scores (18.15 +/- 7.31 and 7.88 +/- 5.32, P < 0.001 respectively). The mean RFS score in the patients was 12.57 and the correlation between RFS score and RSI score was high (r = 0.704). According to the receiver operating characteristic curve analysis the area under curve of the T-RSI was 0.892. The optimal cut-off value was 12.5 with a sensitivity of 82.6% and a specificity of 84.6%. Conclusion. The T-RSI is an easily administered, reliable, and valid instrument for assessing symptoms thought to be related to laryngopharyngeal reflux. A score of T-RSI greater than 12.5 is similar to an RSI score of >13 considered symptomatic for laryngopharyngeal reflux.