Translation and validation of Victorian Institute of Sports Assessment for Gluteal Tendinopathy (VISA-G) questionnaire into Italian

The purpose of the current study was to translate the VISA-G from English into the Italian language (VISA-G-IT), to conduct a cross-cultural adaptation into the Italian context, assessing validity in the Italian context, and to evaluate the VISA-G-IT measurement properties. Translation procedure for the VISA-G questionnaire Beaton’s guidelines for the cross-cultural adaptation of self-reported measures were used (Beaton et al., 2000). In brief: 1. Permission. The developer of the VISA-G Dr. Angie Fearon from University of Canberra was approached by e-mail to requiring both her authorization and her availability to collaborate on the translation process into Italian language of VISA-G questionnaire (Fearon et al., 2015). Dr. Fearon promptly responded by giving us her authorization and willingness to collaborate on our project. 2. Forward translation. The English version of VISA-G will be independently translated into Italian by 2 non-medical professional translators whose native language is English and by a physician whose native language is Italian. Neither of the nonmedical translators are aware of the concepts being investigated or had a medical background. 3. Forward translation - Reconciliation. The 3 Italian translations will be analyzed by a healthcare committee (1 physiatrist, 2 epidemiologists, 1 physiotherapist), which will first ensure that the translations took Italian cultural characteristics into consideration. Discrepancies will be resolved by consensus to achieve conceptual equivalence. 4. Back translation - data acquisition. This consensus version (Italian version 1) will be translated back into English by another non-medical professional translator whose native language is English and that will be blinded to the purpose of the questionnaire and had not seen the original VISA-G questionnaire. 5. Back translation - Reconciliation. The back translated version will be compared to the original version to ensure conceptual equivalence; the remaining discrepancies and ambiguities were resolved between the project manager (AC) and developer (AF) 6. Harmonization. The harmonization group consisted of the back - and forward-translators, and the health committee. At the end the team will agree upon the harmonized version of the Italian VISA-G (VISA-G-IT) questionnaire. All members of the harmonization group will approve the translated versions. 7. Cultural validation. After the committee will confirm the equivalence of the original version and the Italian version of the VISA-G (VISA-G-IT), and the developer will approve the translation, we will perform a pilot test on 10 subjects with a diagnose of GTPS and 10 gender- and age-matched healthy subjects. The main aim of this phase will be to determine whether the subjects understood the questions. Cognitive interviews of 10 patients with a diagnose of GTPS, 10 gender- and age-matched healthy subjects 10 and a researcher and two physiotherapists with relevant clinical experience will conduct to assess the harmonised version of the VISA-G-IT. A researcher trained in cognitive interviewing will conduct these face-to-face interviews maximum 24 hours after each interviewee will completes the VISA-G-IT questionnaire. The time required to complete the questionnaire will take a maximum of 10 minutes, while the interview time will take a maximum of 30 minutes. Each interviewee will be asked whether there were sentences that were difficult to understand. They will be asked what they thought each question meant. The meaning of the items and tasks, as well as the selected responses, will be discussed. This will ensure that the prefinal version will retain adequate equivalence in purpose. All questions should be considered easily understandable by all subjects. 8. Cultural validation - Harmonization. The results from the previous process will be reviewed, and a final version of the VISA-G-IT questionnaire prepared. 9. Final Translation. The version will be proofread and checked for spelling and grammar errors. 10. Assessment of psychometric properties of VISA-G-IT questionnaire. In this phase a sample of convenience will be recruited at a physiotherapy private practice in L'Aquila, Italy. Based on an expected reliability of 0.90, assuming a power of 0.80 and a significance level of 0.05, we calculated that a total sample size of 49 patients with a diagnose of GTPS and 49 gender- and age-matched healthy subjects will be required for the assessment of psychometric properties of VISA-G-IT. Each patient and each healthy subject will be required to complete the VISA-G-IT and the Italian version of the Harris Hip Score questionnaire (HHS-IT) a first time (test) and then a second time after 3 days (re-test). These will allow to evaluate the psychometric properties (reliability and validity) of the VISA-G-IT questionnaire.