The Swedish version of the back pain attitudes questionnaire - Translation, cross-cultural adaptation and validation

Background: Psychosocial factors influence low back pain (LBP) and guidelines recommend assessing unhelpful beliefs. The Back Pain Attitudes Questionnaire (Back-PAQ) is an instrument developed to assess LBP attitudes and beliefs. There is currently no Swedish translation of Back-PAQ. Objectives: To translate and culturally adapt the Back-PAQ into Swedish (Back-PAQ-S) and to test its measurement properties. Design: Study of diagnostic accuracy/assessment scale. Methods: The cultural adaptation followed established guidelines and 120 individuals with and without nonspecific LBP (NSLBP) were recruited for the assessment of Back-PAQ-S's internal consistency, test-retest reliability, standard error of measurement (SEM) and smallest detectable change (SDC). Construct validity was assessed by testing hypotheses regarding Back-PAQ-S's relationship to the Back Beliefs Questionnaire (BBQ) and Tampa Scale of Kinesiophobia (TSK). Results: The Back-PAQ was translated and culturally adapted to Swedish. Expert panelists and informants thought items were relevant, comprehensive, and understandable. Back-PAQ-S of all lengths (34, 20 and 10-items) showed good internal consistency (Cronbach's alpha 0.95, 0.91 and 0.82) and excellent test-retest reliability (Intraclass correlation coefficient (ICC) 0.97, 0.96 and 0.95). The SEM was found to be 4.28, 3.13 and 1.66, and the SDC to be 11.85, 8.68 and 4.59 respectively. The Back-PAQ-S showed high positive correlations (Spearman's rho (rs) 0.78, 0.76 and 0.72) to the BBQ and moderate negative correlations (rs -0.67, -0.50 and -0.69) to the TSK. Conclusion: The Back-PAQ-S has good validity and excellent reliability. It is viable for clinical and research use to assess LBP attitudes and beliefs in Swedish populations with and without NSLBP.