Psychometric testing confirms that the Brazilian-Portuguese adaptations, the original versions of the Fear-Avoidance Beliefs Questionnaire, and the Tampa Scale of Kinesiophobia have similar measurement properties.

Methods: Translation, cross-cultural adaptation, and psychometric testing of 2 questionnaires. Objective: The objectives of this study were to translate and cross-culturally adapt the Fear-Avoidance Beliefs Questionnaire (FABQ) to Brazilian-Portuguese and to test the psychometric properties of the Brazilian-Portuguese versions of the FABQ and the Tampa Scale of Kinesiophobia (TSK).

Background: Self-report measures of fear-avoidance have been widely used in clinical practice and in research. To date there is no Brazilian-Portuguese version of the FABQ and the Brazilian-Portuguese TSK has not yet been comprehensively tested.

Methods: The FABQ was cross-culturally adapted after the recommendations from the Guidelines for the process of cross-cultural adaptation of self-report measures. The Brazilian-Portuguese versions of the FABQ and the TSK were tested for internal consistency, reproducibility, ceiling and floor effects, construct validity, and internal and external responsiveness.

Results: Both instruments yielded high values for internal consistency and reproducibility [(Cronbach's alpha FABQ = 0.93 and TSK = 0.82) and (Intraclass Correlation Coefficient FABQ = 0.96 and TSK = 0.93)]. No ceiling and floor effects were detected in either questionnaire. The FABQ and TSK were highly correlated (r = 0.86) and they were moderately correlated with the pain numerical rating scale at baseline (r = 0.42 and r = 0.43, respectively) showing good construct validity. The TSK was shown to be more responsive than the FABQ in all internal and external responsiveness analyses.

Conclusions: Both the Brazilian-Portuguese versions of the FABQ and the TSK are equally useful in terms of description and identification of patients with fear-avoidance behavior; however, in situations that clinicians or researchers aimed to use fear-avoidance as a follow-up measurement for treatment outcomes it seems that the TSK is the better option due to its better capacity to identify change over time.