EASE-NL : cross-cultural adaptation and validation of the Dutch version of the evaluation of ability to sing easily

Abstract

OBJECTIVES : The Evaluation of the Ability to Sing Easily (EASE) is a self-rating tool that is used to assess the singer's perceptions of the current singing voice status. The purpose of this study was to develop and validate a Dutch translation of the EASE. METHODS : The original version of the EASE was translated and adapted to Dutch according to the recommendations of the Quality of Life Special Interest Group - Translation and Cultural Adaptation group. Subsequently, the questionnaire was individually completed by 70 singers with a mean age of 35.2 years before and after a singing activity, together with a demographic questionnaire and the Dutch Singing Voice Handicap Index 10 (SVHI-10-NL). Two groups of singers were included between September and June 2020: a group of healthy singers (n = 54) and a group of dysphonic singers (n = 16). Internal and external consistency, construct and criterion validity, test-retest and split-half reliability were calculated using Cronbach's alpha coefficients, Student's t-test, the paired Wilcoxon tests and Pearson correlation coefficients. Furthermore, the impact of sex and age and the diagnostic accuracy of the EASE-NL was measured using the Mann Whitney U-test, the One Way ANOVA and the Brown Forsythe ANOVA-test. RESULTS : The internal consistency of the EASE was considered good. For the external consistency, the Pearson correlation coefficient showed a positive correlation between the total score of the EASE-NL and the SVHI-10-NL. Dysphonic singers scored significantly higher compared to singers without voice problems and no differences were found between the pre and post singing condition in both groups. Pearson correlations coefficients showed a strong positive correlation between the test and retest condition and between the subscales. A ROC-curve analysis showed a cut-off score of 12.5, with a sensitivity level of 75.0% and a specificity level of 74.1%. No differences for sex and age were found. CONCLUSIONS : The original English version of the EASE was translated and validated in Dutch. The EASE-NL is found to be a valid and reliable self-reported tool to assess singer's perceptions of the current status of their singing voice.