(n = 15), or an unknown reason (n = 34). Refusals were included and coded as limited health literacy, as these people are likely to perform with limited health literacy skills in real-life settings (e.g. at the doctor’s office) because of their difficulties. Therefore, they were included to maintain the population-representativeness

of the sample and capture a more accurate range of the health literacy skills of the English population. The present analysis thus included 3087 men and women aged 60–75 years (Fig. 1). Health literacy was assessed using a four-item comprehension test based on a fictitious medicine label from the International Adult Literacy Survey (Thorn, this website 2009) (Appendix A). Health literacy was categorised as ‘adequate’ (4/4 questions answered correctly) or ‘limited’ (< 4/4 answered correctly) to capture the point at which adults begin to have difficulty with everyday health tasks. Although whether and how health literacy skills may change over time are uncertain, health literacy scores among our sample

are expected to be stable between data collection and the times of reported CRC screenings (within one year of wave 5 data collection for 59% of those reporting screening and within two years for 96%). Health literacy was also measured at ELSA wave 2 (2004–5) and the scores did not change between waves 2 and 5 within individuals who remained in the study for both waves. Health literacy scores measured PI3K Inhibitor Library at wave 2 were not used for this analysis, as study attrition between waves was differential by health literacy score. Participants were asked if they had ever used a bowel testing kit (i.e. an FOBT kit) and whether the kit was part of the NHS Bowel Cancer Screening Programme. Only 49 out of the 1709 participants (< 3%) who reported having completed an FOBT kit responded that the kit was not part of the NHS programme

and 3 (< 1%) responded that they did not know whether it was part of the programme; hence for this analysis we assume that completion of a Cytidine deaminase FOBT kit equates with participation in the NHS programme. For convenience, the terms “completion of an FOBT kit” and “CRC screening” will hereupon be used synonymously. Sociodemographic covariates were: age, sex (male; female); educational attainment (no qualification; up to degree level; degree level or equivalent); net non-pension wealth (quintiles stratified at age 65 to account for changes in wealth following retirement) (Bostock and Steptoe, 2012); occupational class according to the 2010 National Statistics Socio-economic Classification (routine; intermediate; managerial or professional) (Office for National Statistics, 2010); and ethnic minority status (non-white; white).