Comunicaciones Cortas Cross-cultural adaptation of the Chilean version of the Voice Symptom Scale – VoiSS Equivalencia cultural de la versión Chilena del Voice Symptom Scale – VoiSS

This research aims to accomplish the cross-cultural equivalence of the Chilean version of the VoiSS protocol through its cultural and linguistic adaptation. After the translation of the VoiSS protocol to Chilean Spanish by two bilingual speech therapists and its back translation to English, we compared the items of the original tool with the previous translated version. The existing discrepancies were modified by a consensus committee of five speech therapists and the translated version was entitled Escala de Sintomas Vocales – ESV, with 30 questions and five answers: “Never”, “Occasionally”, “Sometimes”, “Most of the time”, “Always”. For cross-cultural equivalence, the protocol was applied to 15 individuals with vocal problems. In each question the option of “Not applicable” was added to the answer choices for identification of the questions not comprehended or not appropriate for the target population. Two individuals had difficulty answering two questions, which made it necessary to adapt the translation of only one of them. The modified ESV was applied to three individuals with vocal problems, and there were incomprehensible inappropriate questions for the Chilean culture. The ESV reflects the original English version, both in the number of questions and the limitations of the emotional and physical domains. There is now a cross-cultural equivalence of VoiSS in Chilean Spanish, titled ESV. The validation of the ESV for Chilean Spanish is ongoing.


INTRODUCTION
The concern for individuals' quality of life, described in the early 90s (1) , has been highlighted with self-assessment protocols for the impact of a dysphonia (2,3) , used on dysphonic patients during the last two decades. These protocols were created to obtain more data on the development of patients in therapy, and were distributed worldwide in different languages and cultures, with various constructs for their development (4) .
Vocal self-assessment tools were produced from clinical information with data on specific diseases or resulting data to mix general quality of life aspects with voice symptoms (5) . The Voice Symptom Scale -VoiSS is a voice self-assessment tool made with a solid construction (4) , which shows both the voice symptoms and the clinical response to dysphonia treatment (5) . The VoiSS was developed in the United Kingdom and for its use in other locations it must be translated and culturally adapted, as was done in Brazil (6) , according to international standards set out by the Scientific Advisory Committee of Medical Outcome Trust (7) . Therefore, the present study aimed to carry out the cross-cultural equivalence of the Chilean version of the VoiSS protocol, through its cultural and linguistic adaptation.

METHODS
Research was approved by the Research Ethics Committee of the Centro de Especialização em Fonoaudiologia Clínica -CEFAC (CAAE: 39481714.9.0000.5538 and verdict n o 897,370). All participants signed the informed consent.
Firstly, two translations of the VoiSS protocol were obtained (5) in Chilean Spanish by Chilean bilingual speech therapists working in the voice field (T1 = English-Spanish translator number 1; T2 = English-Spanish translator number 2). Then the two translations were compiled in a single translation (SV = Spanish version of the compilation of translations T1 + T2). A back translation was carried out by a third speech therapist fluent in English, who was unaware of the protocol and did not participate in the earlier stages. The back translation, translation and original version were compared by a committee composed of five speech therapist voice specialists. The discrepancies found were modified by consensus, ultimately resulting in the protocol titled Escala de Síntomas Vocales -ESV.
In the cross-cultural equivalence of the ESV, 15 individuals with different kinds or degrees of dysphonia participated in the study, diagnosed by ENT. The ESV protocol questions could be answered with the following: "Never", "Occasionally", "Some of the time", "Most of the time", "Always". In addition, the "not applicable" alternative was added to each question, in order to identify misunderstood or inappropriate phrases for the Chilean population and culture.
Finally, exclusion criteria were applied in cases of illiteracy or protocol misunderstanding, and neurological, cognitive and/or psychiatric disturbances that would prevent proper application of the protocol.

RESULTS
The ESV protocol contains 30 questions, similar to the original version in English. These questions are divided into three domains: 15 questions are concerning limitation (functionality) -e.g., 1-Do you have difficulties to get attention from others using your voice?; 8 questions concerning the emotion domain (psychological) -e.g., 10-Do you feel less valued or depressed due to your voice problem?; and 7 questions belonging to the physical domain (organic symptoms) -e.g., 3-Do you have a sore throat?
At the translation and adaptation stage, 2 individuals from a total of 15 answered the "not applicable" option in various questions (2-Do you have trouble singing? And 24-Do you feel your voice sounds rough and dry?). In the case of question 2, the committee of speech therapists decided not to make modifications since the individual who consigned did not sing, while question 24 itself was modified due to concepts of non-identification of vocabulary, which was as follows: Do you feel that your voice sounds hoarse and dry?. The reformulated ESV was applied to three individuals with impaired speech, in which no cultural and/or conceptual barriers were identified.
The process of adaptation and cultural equivalence of the ESV to Chilean Spanish is abbreviated in Chart 1, and the VoiSS version for Chilean Spanish is listed in Annex A. Chart 1. Process of translation and cultural adaptation of the Voice Symptom Scale -VoiSS (5) for Chilean Spanish

Questions
Original versión in English (

DISCUSSION
The translation and cultural adaptation is a process developed for the population in question, with diverse individuals and types of disorders, in which it is verified whether the translated instrument is applicable to the new culture (7) . In Chile, Spanish protocols are often used that are not culturally validated, therefore it is necessary to insist on a more rigorous process that consists of a cultural adaptation and equivalence consistent with the Chilean reality.
For the adaptation and validation of the ESV in Chilean Spanish, international standards are considered, provided by the Scientific Advisory Committee of Medical Outcome Trust (7) , using what was developed in Brazil as a reference, where it was shown that the adaptation and validation of the VoiSS protocol (5) for that culture can identify the vocal symptoms that respond to dysphonia treatment (6,8) . Validation of assessment tools on the impact of dysphonia generates greater reliability and scientific rigor in clinical practice and research (6) , as is done in other self-assessment tools for the impact of voice problems, which are validated in different languages other than the original (9)(10)(11)(12) . This process is being carried out to obtain the VoiSS protocol in Chilean Spanish.

CONCLUSION
The cross-cultural and linguistic equivalence of the Voice Symptom Scale -VoiSS was verified between its original language and the translated version in Chilean Spanish, Escala de Síntomas Vocales -ESV. Validation of the ESV in Chilean Spanish is under development, once this phase is completed. Annex A. Translated and culturally adapted version of the Chilean Voice Symptom Scale -VoiSS (5) , called Escala de Síntomas Vocales -ESV Gracias por completar este cuestionario ¿Usted respondió todas las preguntas?