Informed decision making in colorectal cancer screening Equal opportunities for disadvantaged groups

Colorectal cancer (CRC) is one of the most common causes of cancer-related deaths. CRC screening has been recommended by several authorities worldwide as it significantly lowers CRC mortality and morbidity. It is important that individuals make an informed decision about participation in screening, as CRC screening has inherent harms, such as false-positive test results and false-negative test results. However, informed decision making about CRC screening is complex; it requires health literacy (HL) skills to weigh up personal benefits and harms of CRC screening to make a decision that reflects one’s personal values. Low HL is more prevalent among disadvantaged groups, including those who are older, have lower education and have a migrant background. In CRC screening programmes, there are social inequalities in access by ethnic background and socioeconomic status. Unequal access to CRC screening among disadvantaged groups is in part based on ‘uninformed’ decision making about participation. HL may serve as an explaining mechanism in the relationship between social inequalities and informed decision making in CRC screening. Examining the potential mediating role of HL in this relationship is essential for supporting informed decision making among disadvantaged groups. In this thesis, we investigated what constitutes informed decision making and explored barriers to informed decision making among disadvantaged groups, assessed how context-based HL should be measured and investigated the role of HL in informed decision making, and examined how informed decision making among individuals with varying HL skills can be supported.