Dr Rebecca Spencer

People with type 2 diabetes (T2DM) are more likely to develop cancer and experience poorer cancer-related outcomes. Despite this, women with diabetes are less likely to participate in cancer screening than women without diabetes. Previous research suggests there are diabetes-related barriers to cancer screening, but very few studies have sought to identify and characterise these barriers. The current PhD aimed to address this research gap, by advancing knowledge and understanding of diabetes-related barriers to cancer screening and potential intervention strategies. Study one undertook a novel, comprehensive systematic review of qualitative research, exploring barriers and facilitators to cancer screening among people living with any type of chronic illness or disability (n = 70 articles). The review revealed a paucity of studies examining bowel cancer screening, and which have been conducted outside the USA. Only one study exclusively examined cancer screening among people with diabetes. Consequently, study two conducted, for the first time, in-depth qualitative interviews examining views and experiences of cervical, breast and bowel cancer screening among women with T2DM in England (n = 25). Interviews identified several diabetes-related barriers and facilitators to cancer screening and potential ways to address and promote these, respectively. Study three developed a novel, brief written intervention (containing a threat and/or coping message), based on Protection Motivation Theory, to address lack of awareness of the T2DM-increased risk of bowel cancer (a key diabetes-related barrier identified in the interviews). An online randomised controlled experiment (n = 349) found no effects of the intervention on cancer screening intentions, likely due in part to a ceiling effect. However, the coping message significantly increased self-efficacy, and decreased response costs and perceived severity. Overall, the thesis findings elucidate how having diabetes can both heighten and add barriers to cancer screening and indicate multifaceted potential intervention targets and strategies to address these.