The Italian version of the Pain Beliefs and Perceptions Inventory: cross-cultural adaptation, factor analysis, reliability and validity.

PURPOSE: To create an Italian version of the Pain Beliefs and Perceptions Inventory (PBAPI-I) and evaluate its psychometric properties. METHODS: The PBAPI was culturally adapted in accordance with international standards. The psychometric testing included factor analysis, investigating reliability by internal consistency (Cronbach's alpha) and test/retest stability (intraclass correlation coefficient, ICC), and exploring construct validity by comparing the PBAPI-I with a pain numerical rating scale (NRS), the Roland Morris Disability Questionnaire (RMDQ), the Pain Catastrophizing Scale (PCS), the Tampa Scale of Kinesiophobia (TSK), the Hospital Anxiety and Depression Score (HADS) and the Chronic Pain Coping Inventory (Pearson's correlation). RESULTS: One hundred and sixty-seven subjects with chronic low back pain (83 % compliance) completed the tool. Factor analysis revealed a three-factor (Time, Mystery and Self-Blame), 16-item solution (explained variance: 80 %). The questionnaire was internally consistent (α = 0.91-0.96), and its stability was good (ICCs = 0.73-0.82). As expected, the construct validity estimates indicated that the Time and Mystery subscales moderately correlated with the NRS (r = 0.33-0.54), RMDQ (r = 0.34-0.47), PCS (r = 0.37-0.49) and TSK (r = 0.30-0.43), whereas the correlations between the Self-Blame subscale and the same measures were poorer. The correlations with the HADS were moderate and poor (anxiety: r = 0.37-0.05; depression: r = 0.39-0.07). Maladaptive coping strategies were more related to pain beliefs than adaptive strategies. CONCLUSION: The PBAPI-I has good psychometric properties that replicate those of other versions.