Development of the Italian version of the Pain Stages of Change Questionnaire in patients with chronic low back pain: cross-cultural adaptation, confirmatory factor analysis, reliability and validity.

Translating, culturally adapting and validating the Italian version of the Pain Stages of Change Questionnaire (PSOCQ-I) to allow its use with Italian-speaking patients with low back pain. The PSOCQ-I was developed by forward-backward translation, a final review by an expert committee and a test of the prefinal version to establish its correspondence with the original English version. Psychometric testing included confirmatory factor analysis, reliability by internal consistency (Cronbach's α) and test-retest reliability (intraclass coefficient correlation), and construct validity by comparing PSOCQ-I with the Pain Catastrophising Scale (PCS), the Tampa Scale of Kinesiophobia (TSK), the Roland Morris Disability Scale (RMDQ), a pain Numerical Rating Scale (NRS), and the Hospital Anxiety and Depression Scale (Pearson's correlation). The questionnaire was administered to 308 patients with chronic low back pain. Factor analysis confirmed a four-factor solution (namely, Precontemplation, Contemplation, Action, and Maintenance), achieving an acceptable data-model fit. Internal consistency (α=0.91-93) and test-retest reliability (intraclass coefficient correlation=0.74-0.81) were satisfactory. Construct validity showed moderate correlations between Precontemplation and PCS (r=0.318), TSK (r=0.385), RMDQ (r=0.320) and NRS (r=0.335); low correlations were found between the other PSOCQ subscales and PCS (r=-0.062; 0.039), TSK (r=-0.164; 0.024), RMDQ (r=-0.073; 0.004) and NRS (r=-0.170; 0.020). Low correlations were found between the PSOCQ-I subscales and anxiety (r=-0.132; 0.150) and depression (r=-0.113; 0.186). The PSOCQ was translated successfully into Italian, and proved to have a good factorial structure and psychometric properties that replicated the results of other versions. Its use is recommended for research purposes.