Validity and reliability of the Turkish version of the low back activity confidence scale (LoBACS)

Abstract

The Low Back Activity Confidence Scale (LoBACS) is a 15-item scale designed to assess low back pain (LBP) through self-efficacy, a key predictor of functional recovery. This study aimed to culturally adapt and evaluate the validity and reliability of the Turkish version of LoBACS in patients with LBP. The translation and adaptation followed Beaton et al.’s protocol. Content and face validity were assessed with a pre-patient group. Both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed to evaluate construct validity. Internal consistency, as well as test-retest reliability, were evaluated in a sample of 150 patients aged 18–70 years. Concurrent validity was measured alongside the Oswestry Back Pain Disability Questionnaire (ODQ) and Quebec Back Pain Disability Scale (QBPDS). Two factors emerged from factor analysis, with item loadings for Functional Self-efficacy (FnSE) ranging from 0.745 to 0.896 and for Self-Regulatory and Exercise Self-efficacy (Self-Reg&ExSE) from 0.817 to 0.940. Cronbach’s alpha was high for FnSE, Self-Reg&ExSE, and the total scale (α = 0.941). Total correlation for each item ranged between 0.770 and 0.925. Test-retest reliability was also high (r = 0.941, p < .01). LoBACS showed moderate agreement with ODQ and QBPDS, demonstrating concurrent validity. In conclusion, the Turkish version of LoBACS is a valid and reliable tool for measuring LBP-related self-efficacy.