Validity and reliability of the Persian version of the trunk impairment scale in people with multiple sclerosis

Background: In order to provide an important measuring tool for the assessment, prognosis of recovery, and treatment of people with multiple sclerosis (PWMS), the aim of this research is to examine the validity and reliability of the Trunk Impairment Scale (TIS) in Persian. Methods: The research included 105 PWMS. The TIS questionnaire was translated and culturally equivalent according to the IQOLA approach. The Intra Class Correlations (ICC) and Cronbach's alpha were used to assess the internal consistency of the questionnaire. Barthel Index (BI), Time Up and Go (TUG), Multiple Sclerosis Walking Scale-12 (MSWS-12), and Trunk Control Test (TCT) scores were correlated with the TIS score in order to assess validity.Results: 86 of 105 participants in this study were female. For several subscales, the ICC correlation coefficient ranged from 0.89 to 0.98. The Cronbach's alpha value of the TIS total score indicates that the TIS questionnaire has quite good internal consistency. (Cronbach's alpha=0.97). The TIS and the MSWS-12, BI, TUG, and TCT questionnaires have correlation coefficients of 0.78, 0.72, 0.60, and 0.71, respectively, indicating strong construct and concurrent validity.Conclusion: The results of the research showed that the TIS in Persian is a relevant and reliable tool for assessing trunk abnormalities in Persian-speaking PWMS.