The authors declare that there are no conflicts of interest. Many thanks to Clare Sheffield and colleagues at Transport for London for providing us with the data used for this study. Census output is Crown copyright and is reproduced with the permission of the Controller

of HMSO and the Queen’s Printer for Scotland. “
“Colorectal cancer (CRC) is the third most common cancer and cause of cancer death in the USA and UK (IARC, 2010). Most BI 6727 in vitro cases (95%) occur in people over 50 years, often co-existing with other lifestyle-related diseases including type 2 diabetes mellitus and cardiovascular disease (CVD) (Baade et al., 2006 and Brown et al., 1993). These diseases share common risk factors including large body size, abnormal lipids and markers of insulin Venetoclax molecular weight resistance (Giovannucci, 2007). The UK government strategy aimed at decreasing CRC burden is focussed on early detection of the disease, and national CRC screening programmes using faecal occult blood testing (FOBT) have been rolled

out across the UK (www.cancerscreening.nhs.uk/bowel). A positive result from screening can focus participants’ attention on risk reduction (McBride et al., 2008), and intervention studies have demonstrated a positive response to dietary guidance (Baker and Wardle, 2002, Caswell et al., 2009 and Robb et al., 2010). However, screening also has the potential to provide false reassurance – the ‘health certificate’ effect, whereby patients who receive negative results feel no need to modify their lifestyle, or have poorer health behaviours than those not participating in screening (Larsen et al., 2007). Both these potential consequences of screening underline the importance of understanding perceptions about disease causes and lifestyle factors, and how these might shape response

to prevention interventions. Messages and advice given by professionals during screening are likely to influence how people interpret and respond to results and treatment, particularly in relation to making subsequent health behaviour changes (Miles et al., 2010). The work reported here was undertaken as part of formative research to gather insight into patients’ perspectives about lifestyle interventions after receiving a positive only CRC screening result. This study was then utilised to inform thinking about recruitment and intervention approaches for the BeWEL study – a randomised controlled trial (RCT), designed to measure the impact of a body weight and physical activity intervention on adults at risk of developing colorectal adenomas (Craigie et al., 2011). The focus of the BeWEL intervention is based on evidence of an association between physical activity, obesity, and diet and risk of CRC and other chronic diseases (Knowler et al., 2002 and World Cancer Research Fund/American Institute for Cancer Research, 2007), and that approximately 43% of CRC can be prevented through changes in these risk factors (WCRF, 2009).