RESEARCH ARTICLE A population-based cross- c

Full list of author information is available at the end of the articleBackground Worldwide, colorectal cancer (CRC) is diagnosed in over one million persons annually and is the fourth leading cause of cancer death [1]. Staging of disease at diagnosis is a critical factor affecting survival. When discovered early, CRC is highly treatable, with a relative five-year survival rate of 90 % for localised CRC [2]. Several randomised controlled trials have demonstrated that CRC mortality can be reduced by 15 % to 33 % through Faecal Occult Blood Test (FOBT) screening, [3-6] with fewer advanced CRCs detected, compared with patients presenting with symptoms, in population-based screen-ing [7]. Although the use of colonoscopy to detect right-sided CRCs is under debate, [8,9] case control and cohort studies of colonoscopy screening suggest a CRC mortality reduction ranging from 60 % to 76 % [10] and incidence reduction of 76 % to 90 % [11]. Approximately 15 % to 25 % of persons who develo