Abstract
Objectives: Participation rates in fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening differ across socio-demographic subgroups. The largest health gains could be achieved in subgroups with low participation rates and high risk of CRC. We investigated the CRC risk within different socio-demographic subgroups with low participation in the Dutch CRC screening program. Study design: Population-based cohort study. Methods: All individuals invited for the Dutch CRC screening program in 2018 and 2019 were included. Data from a previous study, including screening data and demographic characteristics, were augmented with CRC diagnoses in 2018 and 2019. A multivariable logistic regression was used to assess the association between socio-demographic factors and risk of CRC. Results: Overall participation was 72.3% and age-adjusted CRC incidence was 30.3 per 10,000 individuals. Males showed lower participation (69.7%) but had a higher-than-average CRC risk (35.1). The difference in CRC risk between males and females was less pronounced among non-participants (OR: 1.28, 95% CI: 1.20–1.36) than participants (OR: 1.41, 95% CI: 1.35–1.47). Lower income groups also had lower participation (down to 60.0%) and higher risk of CRC (down to 30.7), but the difference in CRC risk between low-income groups and high-income groups was only significant among participants (OR lowest vs highest quintile: 1.22, 95% CI: 1.14–1.32). Conversely, individuals with a Turkish/Moroccan migration background had lower participation (48.7%), but their CRC risk was also lower (18.8; OR: 0.54, 95% CI: 0.46–0.63). Conclusions: CRC risk varies significantly between low-participation groups in the Dutch CRC screening program. Interventions should prioritize the most vulnerable groups, considering both participation and risk of CRC.