Screeners vs. Non-screeners for Colorectal Cancer among People over 50 Years of Age: Factual and Psychological Discriminants.

Abstract

Colorectal cancer (CRC) is the third most frequent form of cancer worldwide, and approximately one third of cases have a positive family history of CRC or associated cancers. Colonoscopy is one of the most effective methods of screening for CRC. Uptake of colonoscopy is suboptimal, and many countries lack a national screening programme. Our study aims at exploring and ranking several factual and psychological variables according to their accuracy in discriminating between screeners and non-screeners for CRC in a convenience sample of people over 50 years of age. The study included 103 individuals aged over 50 years, recruited from day centres for the elderly. We explored socio-demographic variables, frequency of colonoscopy, previous recommendations for screening, health literacy and family history of cancer. Receiver operating characteristic (ROC) analysis was used to establish the discriminative value for each variable between the positive and negative decision for colonoscopy screening. Areas under the curve (AUC) and their equivalent Cohen's d values were calculated. Almost a quarter (25.75%) of participants reported previous colonoscopy screening. ROC curve analysis shows that colonoscopy uptake is best discriminated by perceived benefits of screening (AUC=0.71, d=0.78, p<0.001), previous recommendations for screening (AUC=0.68, d=0.69, p<0.001) and previous recommendations for preventive measures (AUC=0.67, d=0.64, p<0.001). Recommendations from healthcare professionals lead to improved colonoscopy uptake when emphasising the benefits of screening. Results can further inform psychosocial interventions by bringing empirical evidence to emphasize screening benefits and explicit recommendations for individuals at risk for CRC cancer.