International Journal of Colorectal Disease

, Volume 34, Issue 1, pp 141–150 | Cite as

The effects of reminders for colorectal cancer screening: participation and inequality

  • Ulrik DedingEmail author
  • Anna Sharon Henig
  • Christian Torp-Pedersen
  • Henrik Bøggild
Original Article



To investigate the effect of sending out reminders for colorectal cancer screening on socioeconomic and demographic inequalities in screening uptake.


All citizens aged 50–74 in Denmark are invited every 2 years for colorectal cancer screening. Non-participants receive an electronically distributed reminder. Data for these analyses were derived from national registers. Socioeconomic status was measured by income and educational level. Demographic variables included age, gender and marital status, and the analyses were stratified by immigration status. Logistic regression analyses were conducted to estimate the odds of non-participation for invited citizens and for reminded citizens divided by socioeconomic and demographic predictors.


Of 763,511 native Danes invited for screening from 2014 to 2015, 387,116 (50.70%) participated after the initial invitation and 133,470 after receiving a reminder. Differences in participation were present in relation to all subgroups among both the invited citizens and reminded citizens. Differences persisted after full model adjustments with reductions for demographic variables. Odds ratio (OR) for non-participation in the eldest age group was 0.32 (95% CI, 0.32; 0.33) before and 1.11 (95% CI 1, 0.08; 1.14) after the reminder, compared to those under 55 years. OR for the 4th income quartile was 0.54 (95% CI, 0.53; 0.55) before and 0.44 (95% CI, 0.43; 0.45) after the reminder, compared to 1st quartile.


Reminders increased the overall participation, and the inequalities in participation in relation to demographic factors were reduced after the distribution of reminders. The age differences were especially reduced. The inequalities in participation related to socioeconomic status were, however, slightly increased after reminder distribution.


Colorectal cancer screening Reminder Socioeconomic status Inequality Screening 


Compliance with ethical standards

The current study was approved by the Danish Data Protection Agency (Ref. 2008-58-0028, 2016-34). All data in the study were linked and stored in computers held by Statistics Denmark. Data were made available with de-identified personal information. This study only publishes aggregated statistical analyses and results.

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

Retrospective anonymized register-based studies do not require written informed consent and ethical approval [28]. This article does not contain any studies with human participants or animals performed by any of the authors.


  1. 1.
    Van Roosbroeck S, Hoeck S, Van Hal G (2012) Population-based screening for colorectal cancer using an immunochemical faecal occult blood test: a comparison of two invitation strategies. Cancer Epidemiol 36:e317–e324. CrossRefPubMedGoogle Scholar
  2. 2.
    Santare D, Kojalo I, Huttunen T, Rikacovs S, Rucevskis P, Boka V, Leja M (2015) Improving uptake of screening for colorectal cancer: a study on invitation strategies and different test kit use. Eur J Gastroenterol Hepatol 27:536–543. CrossRefPubMedPubMedCentralGoogle Scholar
  3. 3.
    Kerrison RS, McGregor LM, Marshall S et al (2016) Use of a 12 months’ self-referral reminder to facilitate uptake of bowel scope (flexible sigmoidoscopy) screening in previous non-responders: a London-based feasibility study. Br J Cancer 114:751–758. CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Wardle J, Von Wagner C, Kralj-Hans I et al (2016) Effects of evidence-based strategies to reduce the socioeconomic gradient of uptake in the English NHS bowel cancer screening programme (ASCEND): four cluster-randomised controlled trials. Lancet 387:751–759. CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    Deding U, Henig AS, Salling A, Torp-Pedersen C, Bøggild H (2017) Sociodemographic predictors of participation in colorectal cancer screening. Int J Color Dis 32:1117–1124CrossRefGoogle Scholar
  6. 6.
    Wardle J, Miles A, Atkin W (2005) Gender differences in utilization of colorectal cancer screening. J Med Screen 12:20–27. CrossRefPubMedGoogle Scholar
  7. 7.
    Pornet C, Dejardin O, Morlais F, Bouvier V, Launoy G (2010) Socioeconomic determinants for compliance to colorectal cancer screening. A multilevel analysis. J Epidemiol Community Health 64:318–324. CrossRefPubMedGoogle Scholar
  8. 8.
    Frederiksen BL, Jørgensen T, Brasso K, Holten I, Osler M (2010) Socioeconomic position and participation in colorectal cancer screening. Br J Cancer 103:1496–1501. CrossRefPubMedPubMedCentralGoogle Scholar
  9. 9.
    Le Retraite L, Eisinger F, Loundou A et al (2010) Sociogeographical factors associated with participation in colorectal cancer screening. Gastroenterol Clin Biol 34:534–540. CrossRefPubMedGoogle Scholar
  10. 10.
    Van Hal G, Hoeck S, Van Roosbroeck S (2011) Screening for colorectal cancer: sense and sensibilities. Eur J Cancer 47:S156–S163. CrossRefPubMedGoogle Scholar
  11. 11.
    von Wagner C, Baio G, Raine R, Snowball J, Morris S, Atkin W, Obichere A, Handley G, Logan RF, Rainbow S, Smith S, Halloran S, Wardle J (2011) Inequalities in participation in an organized national colorectal cancer screening programme: results from the first 2.6 million invitations in England. Int J Epidemiol 40:712–718. CrossRefGoogle Scholar
  12. 12.
    Pedersen CB (2011) The Danish Civil Registration System. Scand J Public Health 39:22–25. CrossRefGoogle Scholar
  13. 13.
    Thomsen MK, Njor SH, Rasmussen M, Linnemann D, Andersen B, Baatrup G, Friis-Hansen L, Jørgensen JCR, Mikkelsen EM (2017) Validity of data in the Danish colorectal cancer screening database. Clin Epidemiol 9:105–111. CrossRefPubMedPubMedCentralGoogle Scholar
  14. 14.
    Jensen VM, Rasmussen AW (2011) Danish education registers. Scand J Public Health 39:91–94. CrossRefGoogle Scholar
  15. 15.
    Baadsgaard M, Quitzau J (2011) Danish registers on personal income and transfer payments. Scand J Public Health 39:103–105. CrossRefGoogle Scholar
  16. 16.
    Helweg-Larsen K (2011) The Danish Register of Causes of Death. Scand J Public Health 39:26–29. CrossRefGoogle Scholar
  17. 17.
    Lynge E, Sandegaard JL, Rebolj M (2011) The Danish National Patient Register. Scand J Public Health 39:30–33. CrossRefGoogle Scholar
  18. 18.
    Larsen MB, Mikkelsen EM, Rasmussen M, Friis-Hansen L, Ovesen A, Rahr HB, Andersen B (2017) Sociodemographic characteristics of nonparticipants in the Danish colorectal cancer screening program: a nationwide cross-sectional study. Clin Epidemiol 9:345–354CrossRefPubMedPubMedCentralGoogle Scholar
  19. 19.
    OECD (2013) OECD framework for statistics on the distribution of household income, consumption and wealth. Accessed 22 Jun 2018
  20. 20.
    Danmarks Statistik (2016) Statistikdokumentation for Indvandrere og efterkommere 2016. Accessed 22 Jun 2018
  21. 21.
    R Core Team (2016) R: a language and environment for statistical computingGoogle Scholar
  22. 22.
    Raine R, Moss SM, Von Wagner C et al (2016) A national cluster-randomised controlled trial to examine the effect of enhanced reminders on the socioeconomic gradient in uptake in bowel cancer screening. Br J Cancer 115:1479–1486. CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Smith SG, Wardle J, Atkin W, Raine R, McGregor LM, Vart G, Morris S, Duffy SW, Moss S, Hackshaw A, Halloran S, Kralj-Hans I, Howe R, Snowball J, Handley G, Logan RF, Rainbow S, Smith S, Thomas M, Counsell N, von Wagner C (2017) Reducing the socioeconomic gradient in uptake of the NHS bowel cancer screening programme using a simplified supplementary information leaflet: a cluster-randomised trial. BMC Cancer 17:1–9. CrossRefGoogle Scholar
  24. 24.
    Lee JK, Groessl EJ, Ganiats TG, Ho SB (2011) Cost-effectiveness of a mailed educational reminder to increase colorectal cancer screening. BMC Gastroenterol 11:1–8. CrossRefGoogle Scholar
  25. 25.
    Vidal C, Garcia M, Benito L, Milà N, Binefa G, Moreno V (2014) Use of text-message reminders to improve participation in a population-based breast cancer screening program. J Med Syst 38:1–7. CrossRefGoogle Scholar
  26. 26.
    Hirst Y, Skrobanski H, Kerrison RS, Kobayashi LC, Counsell N, Djedovic N, Ruwende J, Stewart M, von Wagner C (2017) Text-message Reminders in Colorectal Cancer Screening (TRICCS): a randomised controlled trial. Br J Cancer 116:1408–1414. CrossRefPubMedPubMedCentralGoogle Scholar
  27. 27.
    Gregory T, Cole SR, Wilson CJ, Flight IH, Zajac IT, Turnbull D, Young GP (2013) Exploring the validity of the continuum of resistance model for discriminating early from late and non-uptake of colorectal cancer screening: implications for the design of invitation and reminder letters. Int J Behav Med 20:572–581. CrossRefPubMedGoogle Scholar
  28. 28.
    Thygesen LC, Daasnes C, Thaulow I, Bronnum-Hansen H (2011) Introduction to Danish (nationwide) registers on health and social issues: structure, access, legislation, and archiving. Scand J Public Health 39:12–16. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Health Science and Technology, Public Health and Epidemiology GroupAalborg UniversityAalborg ØstDenmark
  2. 2.Unit of Epidemiology and BiostatisticsAalborg University HospitalAalborgDenmark

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