Factorial structure and measurement invariance of the Cancer Behavior Inventory-Brief Chinese version in cancer patient and family caregiver dyads

The Cancer Behavior Inventory-Brief (CBI-B) version represents a reliable, valid and non-burdensome measure of self-efficacy. The factorial structure of the CBI-B, however, remains inconclusive. This study was designed to validate the factorial structure of the CBI-B Chinese version (CBI-B/C) when applied in samples of cancer patient (CP) and family caregiver (FC) dyads, and to estimate the CBI-B/C measurement invariance in CP-FC dyads. A total of 772 CP-FC dyads completed the questionnaire evaluating demographic and disease characteristics and self-efficacy. The investigation was conducted from November 2014 to December 2015. The factorial structure of the CBI-B/C was evaluated using exploratory and confirmatory factor analysis. The CBI-B/C measurement invariance in CPs and FCs was examined by paired T-test and Pearson correlations. A single-factor structure of the CBI-B/C was selected as the ultimate solution. CBI-B/C reliability was approved by all Cronbach’s α ≥0.920 in samples of both CPs and FCs. With the exception of item 10, FCs had higher levels of confidence in coping with cancer than did the CPs. All correlations of the 12 items between CPs and FCs were significant (r = 0.238–0.357). The current analysis offers a satisfactory single-factor construct of the CBI-B/C in Chinese samples of CP and FC dyads. The relatively lower levels of self-efficacy and measurement invariance of self-efficacy in CPs and their FCs underscore the significance of treating CPs and their FCs as a unit, and the need to develop interventions to foster dyadic self-efficacy for coping in CP-FC dyads.