Decision-making in cancer preventive therapy

Aspirin is increasingly recommended for cancer preventive therapy. In the United Kingdom (UK), the National Institute for Health and Care Excellence recommends (NG151) aspirin to prevent colorectal cancer in people with Lynch syndrome. Future UK guidance may recommend aspirin for those at population risk of colorectal cancer, similar to Australian guidance. In the thesis, I aimed to investigate the barriers and facilitators affecting use of aspirin for preventive therapy among people with Lynch syndrome and the UK public. I also investigated the barriers to healthcare providers recommending and prescribing aspirin. Study One is a systematic review synthesising the data on behaviour and attitudes in the context of aspirin for cancer prevention. This review found substantial scope for behavioural research into the factors affecting aspirin use. Study Two involved qualitative interviews exploring the views of people with Lynch syndrome and healthcare providers. Patients and GPs had multiple unmet informational needs in decisions concerning aspirin, which are inconsistently supported by current care pathways. Study Three was a mixed methods study recruiting the UK public aged 50 to 70. I observed mixed acceptability towards taking aspirin for colorectal cancer prevention, with concerns among participants on the necessity of the medication and the side-effects. Study Four investigated the optimal type and level of information to communicate with GPs to increase their willingness to prescribe aspirin for a hypothetical patient with Lynch syndrome. Across the factorial trial conditions, I manipulated the presence or absence of three information components: 1) national guidance; 2) trial evidence; 3) information comparing the risks and benefits of aspirin. I found no statistically significant main effects or interactions of the three components on willingness to prescribe. Overall, coordinated and multilevel strategies are warranted, addressing the needs of people with Lynch syndrome, the UK public, and GPs.