Validation of voice scales into Spanish: Systematic review of the psychometric properties

Introduction

To use a test in a language or culture other than the original it is necessary to carry out, in addition to its adaptation, a psychometric validation. This systematic review assesses the validation studies of the voice self-report scales in Spanish.

Methods

A systematic review was performed searching ten databases. The assessment was carried out following the criteria proposed by Terwee et al. (2007) together with some specifically proposed for this study. Validation studies in Spanish of self-report voice scales published in indexed journals were included and the search was updated on February 2nd, 2023.

Results

15 studies that evaluated 12 scales were reviewed. It was verified that not all the validations were adjusted to the criteria used and that the properties to verify the metric strength of the validations were, in general, few.

Conclusions

This systematic review shows that the included studies do not report much evidence of metric quality. It should be considered that different strategies have currently been developed to obtain more and better evidence of reliability and validity. Our contribution is to reflect on the usual practice of validation of self-report scales in Spanish language. The most important weakness is the possibility of using broader and more current evaluation protocols. We also propose to continue this work, completing it with a meta-analytic study.