Abstract PR-01: Inequalities in colorectal cancer screening uptake: Results from the first 2.6 million invitations in the organized screening program in the U.K
Authors: von Wagner Christian , Baio Gianluca , Raine Rosalind , Snowball Julia , Morris Stephen , Atkin Wendy , Obichere Austin , Handley Graham , Logan Richard , Rainbow Sandra , Smith Stephen , Halloran Stephen , Wardle Jane 
Published: January 2011

Abstract
Background: An organized, population-based colorectal cancer (CRC) screening program was initiated in England in 2006, offering biennial Fecal Occult Blood testing (FOBt) to adults aged 60 to 69 years, with abnormal results followed up by colonoscopy. Because organized programs use population records to contact all eligible adults by mail, and there are no costs associated with screening or follow-up in the UK National Health Service, barriers to access for lower SES groups should be minimized. However, socioeconomic (SES) differences have been observed across a range of early detection behaviors, making it important to monitor the implementation of a new screening program. The aim of this analysis was to identify the extent of inequalities in uptake by SES, ethnic diversity, gender, and age in the English screening program.
Methods: Between October 2006 and January 2009, over 2.6 million adults aged 60-69 years were mailed a first FOBt kit by one of the five regional “Hubs.” Area-level SES was indexed with a composite indicator (the Index of Multiple Deprivation) based on census-derived indicators of income, education, employment, environment, and housing for each postcode sector (containing an average of 3,000 addresses). Area-level ethnic diversity was based on the proportion of nonwhite residents in each postcode sector. Gender and age data were obtained from the Hubs. Screening uptake was defined as return of a test kit within 13 weeks, recorded by the Hub. We used multivariate generalized linear regression to examine variation in uptake by deprivation, ethnicity, gender, and age.
Results: Over the study period, 2,658,859 FOBt kits were mailed out, of which 54% were returned. Uptake rates showed a linear gradient across quintiles of deprivation, ranging from 35% in the most deprived quintile to 61% in the least deprived. Multivariate analyses confirmed a significant independent effect of deprivation after adjusting for ethnicity, gender, age and Hub. The association between deprivation and uptake was stronger in women and older people. The most ethnically diverse quintile of areas also had lower uptake rates (38%) than other areas (52% to 58%), independent of SES, age, gender, and Hub. Ethnic disparities were more pronounced in men but equivalent across age groups. More women than men returned a kit (56% vs. 51%). Uptake increased with age in men (49% at 60-64 years; 53% at 65-69 years) but not in women (57% vs. 56%).
Conclusion: Uptake of FOBt in the new national CRC screening program in England is encouraging, but these results demonstrate that even though organized programs provide equitable delivery of the opportunity to screen, they do not eradicate inequalities in uptake. The lower uptake associated with ethnic diversity was apparent only in the most diverse quintile, which predominantly comprised inner city areas. In contrast, SES inequalities not only meant dramatically reduced uptake in the most deprived quintile but also showed a linear gradient in uptake across the entire SES spectrum. Reducing inequalities in uptake will require understanding how SES influences screening decision making. Organized programs do not obviate the need for action to promote equality of uptake if they are to avoid creating increased inequalities in cancer mortality.
Citation Information: Cancer Prev Res 2010;3(12 Suppl):PR-01.