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Research Christmas 2008: Seasonal Fayre

Appointments timed in proximity to annual milestones and compliance with screening: randomised controlled trial

BMJ 2008; 337 doi: (Published 18 December 2008) Cite this as: BMJ 2008;337:a2794
  1. Geir Hoff, professor of medicine and head of hospital research123,
  2. Michael Bretthauer, gastrointestinal endoscopist and editorial fellow145
  1. 1Cancer Registry of Norway, Oslo, Norway
  2. 2Department of Medicine, Telemark Hospital, Norway
  3. 3University of Oslo
  4. 4Department of Gastroenterology, Rikshospitalet University Hospital, Oslo
  5. 5New England Journal of Medicine, Boston, USA
  1. Correspondence to: G Hoff, Cancer Registry of Norway, Majorstuen, 0304 Oslo, Norway hofg{at}
  • Accepted 13 October 2008


Objective To investigate whether appointments for screening timed in proximity to annual milestones (birthdays, Christmas and New Year) may be used as a strategy to improve attendance for screening for colorectal cancer.

Design Randomised controlled trial.

Setting City of Oslo (urban) and Telemark county (urban and rural), Norway.

Participants 12 960 screened adults (64.7% of those invited).

Main outcome measure Attendance rates for each week and month of assigned appointment.

Results Attendance rates were significantly higher in December than the rest of the year (72.3% v 64.6%, P<0.001) in adults who received an invitation in the week of their birthday or were assigned to screening in the first or second week after their birthday (67.9% v 64.5%, P=0.007). This effect was most pronounced in the urban population of Oslo. In a multivariable logistic regression model, attendance improved in those who received an invitation in the week of their birthday or were assigned to screening in the first or second week after their birthday (odds ratio 1.15, 95% confidence interval 1.03 to 1.28) and those who were assigned to screening in December (odds ratio 1.45, 1.16 to 1.82).

Conclusion Attendance rates for screening for colorectal cancer were higher in December and around attendees’ birthdays, the latter particularly in an urban population. Compliance with screening programmes may therefore be improved by timing invitations in proximity to annual milestones.

Trial registration Clinical Trials NCT00119912.


  • Contributors: GH conceived the study and did the statistical analyses. Both authors drafted and refined the manuscript and both had full access to all data. Frøydis Langmark, director of the Cancer Registry of Norway, Oslo, is guarantor.

  • Funding: The Norwegian Colorectal Cancer Prevention Trial was funded by grants from the Norwegian Cancer Society and the Norwegian Department of Health. The authors are independent from the funders of that study.

  • Competing interests: None declared.

  • Ethical approval: This study was approved by the regional ethics committee. The National Institute of Data Inspection approved the study protocol of the Norwegian Colorectal Cancer Prevention Trial 1.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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