The Effect of a Colorectal Cancer Screening Decision Aid Tailored for People With Lower Educational Attainment in the Central Denmark Region on Colorectal Cancer Knowledge and Colorectal Cancer Screening Attitude and Participation Rate

Study setting The Danish national colorectal cancer (CRC) screening programme was implemented in Denmark in March 2014. All citizens aged 50-74 years are invited to take up CRC screening biennially, however, the first prevalence round is carried out during a four year period (2014-2017). During the this period, citizens are invited according to month of birth, except citizens aged 49 who are invited just before they turn 50 and citizens turning 75 who are invited prior to their 75th birthday, if they were not invited earlier in the program.

Politically and organisationally the CRC screening programme is nationally directed, but the administrative responsibility is placed within the five regions in Denmark. The Department of Public Health Programmes is responsible for the administration of the CRC screening programme in the Central Denmark Region (CDR).

The CDR has 1.3 million citizens (23% of the total population) of which roughly 390 000 citizens are 50-74 years of age. The citizens receive an invitation, containing a screening kit. The screening test (collection of a stool sample) is performed in the citizen's own home. The stool sample is sent to the clinical biochemical department at the hospital. If the citizens do not return a stool sample within 45 days after receiving the invitation, a screening reminder is received. Citizens, who still do not return a stool sample, are automatically referred to the next screening round, and will receive another invitation two years later. Citizens with a negative test are automatically referred to the next screening round. Citizens with a positive test are invited to have a colonoscopy.

Since 2010, national digitisation has occurred in Denmark. Hence, communication to and from Danish authorities occur via digital mail, in the public email platform E-Boks. Danish residents are obliged to order a digital signature (NemID) which is used as a shared log-in for E-boks, public and private online self-services, and online banking. Only disabled citizens (e.g. physical or cognitive impairment) or citizens unable to satisfactorily identify themselves (e.g. migrants with no permanent resident permit) can be exempted from ordering a NemID. As of May 2016 more than 5 million Danish citizens (87.5% of the entire population including children) have access to E-boks. Exemption from digital communication has been granted to 9.8% of Danish Residents aged 45-74 years.

All letters in the CRC screening programme are sent by digital mail, except from invitation letters, which contains a screening kit and are sent by conventional mail. Citizens exempt from digital communication receive conventional letters via a remote printing system.