Validation of the Brief Version of the Cancer Behavior Inventory in Breast Cancer Portuguese Patients.

Self-efficacy is a coping resource with a positive impact on well-being, quality of life, anxiety, and depression in cancer patients, even after treatment. This study focused on the validation of the Cancer Behavior Inventory-Brief Version (CBI-B) in Portuguese patients with breast cancer. The study included 115 patients with breast cancer receiving outpatient chemotherapy in four hospitals located in Portugal. Participants (N = 115) completed the translated version of the CBI-B in Portuguese and measures of quality of life (QLQ- C30), psychological distress (HADS), and illness perceptions (IPQ-B). Confirmatory factor analysis supported the four-factor original structure of the CBI-B. The Portuguese version of the CBI-B showed good psychometric properties as shown by measures of internal consistency (Cronbach's alpha = .88), test-retest reliability (intraclass correlation coefficient = .59), convergent validity with the QLQ-C30 (r = .43, p < .001), and divergent validity with the HADS (r = -.60, p < .001) and the IPQ-B (r = -.51, p < .001). The Portuguese version of the CBI-B is a valid and reliable instrument to evaluate the self-efficacy for coping in Portuguese breast cancer patients. Future studies should validate the CBI-B in patients with other types of cancer.