Supplementary Material for: Development of a new self-assessment tool for laryngopharyngeal reflux screening in singers (SVHI-12-LPR)

Introduction: The present study aims to develop a new tool for the evaluation of singers with self-reported symptoms suggestive of LPR (the SVHI-12-LPR), by correlating RSI with SVHI in a population sample of 163 subjects (both professional and amateur singers), evaluated also by videolaryngostroboscopy. This study is a cross-sectional double observational study. Methods: RSI and SVHI were administered to 159 singers (amateurs, singing students and professional singers). All subjects underwent videolaryngostroboscopy to objectively identify four subgroups: normal subjects (41.5%), subjects with organic lesions occupying the glottic space (17.6%), subjects with functional dysphonia (18.2%), subjects presenting solely signs suggestive of LPR (22.6%). Using the validated RSI threshold, 33.9% of participants presented an RSI total score >13, suggestive of LPR. Results: Subjects with a suspected diagnosis of LPR at videolaryngostroboscopy presented a mean RSI significantly higher than other subgroups (p<0.001). Moreover, the SVHI-36 score did not statistically differ between pathological subgroups. A significant positive relationship was observed between RSI and SVHI total score (Spearman’s rank correlation coefficient (rho) = 0.474, p< 0.001). 12 SVHI items (items 1, 2, 4, 5, 6, 7, 12, 20, 24, 25, 26, 30) showed a significant association with RSI pathology classification. Statistical analysis demonstrated for the 12 selected items (SVHI-12-LPR) acceptable specificity (0.691) and sensibility (0.833) for the suspected diagnosis of LPR with a cutoff of 15. Conclusions: From the SVHI-36, 12 items were extracted that correlated with the specific impact that LPR has on the singer’s voice (SVHI-12-LPR), as evaluated by RSI and videolaryngostroboscopy. Such questionnaire represents a new tool that could be applied to singers with symptoms suggestive of LPR, to select which patients would benefit from a further phoniatric and videolaryngostroboscopic evaluation.