Factorial validity and invariance of a survey measuring psychosocial correlates of colorectal cancer screening among African Americans and Caucasians

Background: Psychosocial constructs are widely used to predict colorectal cancer screening and are targeted as intermediate outcomes in behavioral intervention studies. Reliable and valid instruments for measuring general colorectal cancer screening psychosocial constructs are needed; yet, few studies have conducted psychometric analyses. This study replicated a five-factor structure for 16 theory-based, general colorectal cancer screening items measuring salience and coherence, cancer worries, perceived susceptibility, response efficacy, and social influence. In addition, we examined factorial invariance across race and sex. Methods: African American and Caucasian patients (n = 1,413) attending an urban, primary care clinic were included in this study. These individuals completed a baseline survey as part of a colorectal cancer screening intervention trial. Single and multigroup confirmatory factor analyses using maximum-likelihood estimation were done. Results: The five-factor general colorectal cancer screening model provided excellent fit and was invariant across race-sex subgroups. Conclusions: The findings of invariance across sex and race subgroups support the use of these scales to measure group differences.