Reliability and Validity of the Tampa Scale of Kinesiophobia Questionnaire in Individuals with Non-specific Low Back Pain

Background: The Tampa Scale of Kinesiophobia (TSK) is considered a valid and reliable tool to assess the fear-avoidance behavior in patients. There is a valid and reliable Persian version of the TSK-17. Objectives: The present study aimed to assess the internal consistency as a measurement for the test reliability and factor (domain) validity of the Persian version of the TSK-17 to determine whether a modified form can be proposed. Methods: This study analyzed the data of 295 individuals with non-specific low back pain (NSLBP). Cronbach’s alpha was used to assess internal consistency (reliability). Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were applied to evaluate factor validity which is an aspect of the construct validity. The Chi-square divided by the degrees of freedom, the goodness of fit index (GFI), the confirmatory fit index (CFI), and the root mean square error of approximation (RMSEA) indices were utilized as the goodness-of-fit criteria. Data analysis was performed using SPSS software (version 18), AMOS software (version 20), and EQS software (version 6.2). Results: Two factors were extracted for the TSK-17 questionnaire using EFA, and then the structure was confirmed with CFA. Cronbach’s alpha as an internal consistency index was 0.949 for the entire questionnaire, 0.931 for the 11-item fear-of-movement factor, and 0.971 for the 6-item belief factor. The evaluation of the inappropriate items demonstrated that no items were selected for the deletion; therefore, a modified version of the TSK was not presented. The goodness-of-fit indices were reported as GFI = 0.882, RMSEA=0.066 (90% CI: 0.055-0.076), CFI = 0.983, and minimum discrepancy per degree of freedom = 2.27. Conclusions: The Persian version of the TSK-17 can be considered a valid and reliable tool to assess the fear of movement and avoidance behavior in individuals with NSLBP.