Decision-making about participation in colorectal cancer screening in Sweden: Autonomous, value-dependent but uninformed?

Abstract

To investigate knowledge, values and preferences, and involvement among screening participants and non-participants in relation to colorectal cancer (CRC) and screening decision. Individuals (N = 2748) from the Screening of Swedish Colons trial were invited to respond to the SCREESCO questionnaire, assessing information/knowledge, values/preferences, and involvement. Respondents' (screening participants, n = 1320; non-participants, n = 161) knowledge varied across items; 90 % recognised faecal blood as a CRC symptom, but less than half cited overweight, smoking, alcohol, and physical inactivity as risk factors. Incidence and case fatality were often over- and underestimated, respectively (>45 and 40 %). Non-participants were more uncertain about their CRC risk (p = 0.015) and less convinced that screening reduces the risk of dying from CRC (p < 0.001). In decision-making, screening participants took most into consideration the importance of early detection and CRC worry, and non-participants the risk of discomfort and complications due to the screening examination (p < 0.001). Most individuals made the decision without involving others. For informed and shared decisions, efforts need to be made to increase public knowledge about CRC and to develop interventions to support individuals in decision-making. These results can inform and guide future initiatives to facilitate high quality decisions and CRC screening uptake in Sweden.