A 7-item Tampa Scale for Kinesiophobia in people with femoroacetabular impingement syndrome: evaluation of structural validity, hypothesis testing, internal consistency and minimally important change

Abstract

Abstract Background The 17-item Tampa Scale for Kinesiophobia (TSK) is a commonly used patient-reported outcome measure (PROM) to assess kinesiophobia, but the measurement properties of the TSK in people with femoroacetabular impingement syndrome (FAIS) are unknown. Objectives 1) Revise the existing TSK by removing items, as needed, with inadequate functioning to optimise the TSK for people with FAIS, and 2) evaluate construct validity (both structural validity and hypothesis testing), internal consistency, and minimal important change. Methods Cross-sectional cohort study including 153 young adults with FAIS. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to evaluate structural validity and the TSK was revised to remove items with poor function, improving CFA model fit. Hypothesis testing, internal consistency (Cronbach's α) and minimal important change (distribution-based method) were also evaluated. Results A 7-item version of the TSK provided the best CFA model fit with 10-items functioning poorly and needing to be removed. The 7-item TSK was uni-dimensional (single factor in EFA) and had adequate structural validity (Standardised Root Measure Square = 0.0771). The 7-item TSK had insufficient hypothesis testing with moderate correlations to 8/14 PROMs measuring different constructs. The 7-item TSK had adequate internal consistency (α = 0.783). The minimal important change of the 7-item TSK was 6.00 points (0–100 point scale). Conclusion We found that the ‘7-item TSK for FAIS’, had superior structural validity to the original 17-item scale, suggesting that it may be more appropriate for use in this population. Further studies should evaluate other measurement properties of the 7-item scale.