Brief Fear of Movement Scale for osteoarthritis.

OBJECTIVE: Fear of movement has important clinical implications for individuals with osteoarthritis (OA). This study aimed to establish a brief fear of movement scale for use in OA. Items from the Tampa Scale for Kinesiophobia (TSK) were examined.
METHODS: The English version of the TSK was examined in a community-based sample (n = 1,136) of individuals with OA of the hip or knee. Exploratory and confirmatory factor analyses were used to determine the number and content of the dimensions of fear of movement. Factorial invariance was tested across subgroups of sex, race, education, and OA severity. Convergent validity with measures of pain, physical functioning, and psychological functioning was examined.
RESULTS: Factor analyses identified a single-factor 6-item scale that measures activity avoidance due to pain-related fear of movement (confirmatory factor analysis indices of model fit: root mean square error of approximation = 0.04, standardized root mean square residual = 0.01, comparative fit index = 0.99, and Tucker-Lewis Index = 0.99). The 6-item scale demonstrated factorial invariance across sex, race, levels of education, and OA severity, suggesting that this scale performs consistently across diverse groups of individuals with OA. Convergent validity with measures of pain (β = 0.30-0.41), physical functioning (β = 0.44-0.48), and psychological functioning (β = 0.36-0.37) was also demonstrated.
CONCLUSION: The Brief Fear of Movement Scale identified in this study provides a promising and valid approach for assessing fear of movement in individuals with OA. This brief scale demonstrated several important strengths, including a small number of items, sound psychometric properties, and consistent performance across diverse groups of individuals with OA.