The Fremantle Back Awareness Questionnaire: Cross-cultural adaptation, validity and reliability of the Polish version

Background: Body image disturbance is observed in individuals with chronic low back pain (CLBP) and is a potential treatment target. The Fremantle Back Awareness Questionnaire (FreBAQ) is designed to identify disrupted body image specific to the low back. This study aimed to develop and assess the measurement properties of a Polish language version of this questionnaire (FreBAQ-PL). Methods: Following the translation process, cognitive interviews were carried out as a qualitative assessment of content validity. Subsequently a quantitative assessment of content validity was undertaken among in a study sample with CLBP and experts. Measurement properties were assessed in 114 participants with CLBP and 53 pain-free participants. The CLBP sample repeated the FreBAQ-PL assessment within 14-days. The measurement properties assessed in this study were content validity, internal consistency, frequency of responses, known-groups validity, convergent validity and test–retest reliability. Results: Content validity was supported, affirming relevance and comprehensiveness. Known-groups validity was confirmed by significant differences in FreBAQ-PL scores between participants with CLBP and pain-free participants (p < 0.05). Convergent validity was established through moderate associations between FreBAQ-PL scores and pain variables (intensity and duration) (ρ′s = 0.24–0.27, p's < 0.01), disability (ρ = 0.34, p < 0.01), kinesiophobia (ρ = 0.37, p < 0.01), depression (ρ = 0.30, p < 0.01) and anxiety (ρ = 0.24, p < 0.01). The scale was internally consistent (Cronbach's alpha 0.81). Test–retest reliability was good (ICC 0.90). Conclusions: The FreBAQ-PL is a reliable, internally consistent, and valid measure that can be used in clinical and research settings to assess the presence of body image disturbance in Polish-speaking individuals with CLBP.