Singing Voice Handicap Index-12 Development and validation of a German version

Background The aim of this study was to develop a shortened German version of the Singing Voice Handicap Index (SVHI). The SVHI is a one-dimensional instrument for self-assessment of a voice disorder in singers. The questionnaire developed in the USA comprises 36 items and has been available in a validated German version since 2013. Methods Bicentric data from a total of 200 patients formed the basis for item analysis and selection. Using corrected item-total correlations, 12 items were selected for the abridged version. The internal consistency was calculated. The SVHI-12 was subsequently validated in 97 vocal patients and 105 vocally healthy singers (control group) using the test-retest procedure. Results The SVHI-12 achieved a good internal consistency (Cronbach's alpha = 0.93) and a good test-retest reliability (intra-class correlation r = 0.88 ; p < 0.001). The patients had significantly higher overall scores (18 +/- 13 vs. 7 +/- 6) compared to the healthy control group. The SVHI-12 overall score correlated significantly positively with the severity of the voice disorder as reported by the patient (r = 0.68; p < 0.001). As a threshold value above which a voice can be described as disturbed, a total score > 7 points was calculated using receiver operating curve analysis. As an indication of a voice disorder, a sensitivity of 81% and a specificity of 71% is thus achieved (Youden index 0.523, area under the curve 0.827, 95% confidence interval 0.769-0.885). Conclusion The shortened SVHI has similarly good psychometric characteristics to the original SVHI. With the SVHI-12, a valid and effective instrument for the detection of singing voice disorders is available for German-speaking countries.