Abstract
Trismus refers to restriction in the ability to open the mouth. Comprehensive evaluation of trismus and its treatment outcomes needs a multidimensional, self-administered, trismus specific tool. In the present scenario, Gothenburg trismus questionnaire is the only reliable instrument to quantify trismus. Translation of this questionnaire helps in providing standardized documentation of trismus related problems and to obtain a patient's perspective on treatment outcomes within various populations. The aim of this study was to translate the Gothenburg trismus questionnaire-2 (GTQ 2) into Telugu (one of the Indian Languages) and validation of the translation for its effective use in regional Telugu speaking patients. The GTQ 2 was translated according to the guidelines framed by the International Society for Pharmacoeconomics and Outcomes Research: (1) forward translation, (2) reconciliation and back translation, (3) cognitive debriefing, and (4) pilot testing. The psychometric properties of the translated version were evaluated by testing its internal consistency, construct validity, known-group validity and floor and ceiling effects. Patients who reported with or without trismus to the Head and Neck Oncology outpatient clinic were enrolled for the study. Comparison of the GTQ scores was done using Mann-Whitney U-test. The Pearson correlation coefficient was used for assessing convergent and divergent validity. Internal Consistency was calculated using Cronbach's alpha coefficient. The translated version of the GTQ 2 was administered to 60 patients (30 trismus patients and 30 non-trismus patients). GTQ 2 was successfully translated without any significant issues. Construct validity of the translated version was confirmed and it has a good internal consistency (α > 0.7). The translated instrument can differentiate between those with and without trismus (p < 0.0005). A valid and reliable Telugu version of the Gothenburg Trismus Questionnaire-2 is now available for the benefit of Indian patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13193-021-01369-7.