Intended for healthcare professionals

Information In Practice

Presentation on websites of possible benefits and harms from screening for breast cancer: cross sectional study

BMJ 2004; 328 doi: (Published 15 January 2004) Cite this as: BMJ 2004;328:148
  1. Karsten Juhl Jørgensen, physician1,
  2. Peter C Gøtzsche, director (pcg{at}
  1. 1Nordic Cochrane Centre, H:S Rigshospitalet, DK-2100 København ø, Denmark
  1. Correspondence to: Peter C Gøtzsche
  • Accepted 9 November 2003


Objective To investigate whether information on mammographic screening presented on websites by interest groups is balanced, is independent of source of funding, and reflects recent findings.

Design Cross sectional study using a checklist with 17 information items.

Setting 27 websites in Scandinavian and English speaking countries.

Results The 13 sites from advocacy groups and the 11 from governmental institutions all recommended mammographic screening, whereas the three from consumer organisations questioned screening (P = 0.0007). All the advocacy groups accepted industry funding, apparently without restrictions. In contrast the three consumer organisations acknowledged the risk of bias related to industry funding, and two of them did not accept such funding at all. Advocacy groups and governmental organisations favoured information items that shed positive light on screening. The major harms of screening, overdiagnosis and overtreatment, were mentioned by only four of these groups, but by all three sites from consumer organisations (P = 0.02). In addition, the chosen information was often misleading or erroneous. The selection of information items for websites did not reflect recent findings, apart from the consumer sites, which were much more balanced and comprehensive than other sites (median of 9 information items v3 items, P = 0.03).

Conclusions The information material provided by professional advocacy groups and governmental organisations is information poor and severely biased in favour of screening. Few websites live up to accepted standards for informed consent such as those stated in the General Medical Council's guidelines.


  • Contributors PCG conceived the project, KJJ wrote the draft protocol, did the searches, and wrote the first manuscript. Both authors extracted data and contributed to the protocol and the manuscript. Both are guarantors

  • Funding None.

  • Competing interests One of the authors was involved in the systematic review of breast screening trials that questioned the value of screening.

  • Accepted 9 November 2003
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