Transparency regarding experts' conflicts of interest is important for the credibility of national clinical guidelines. We examined conflicts of interest among authors of the Norwegian Directorate of Health's action plans for cancer.

We asked the Norwegian Directorate of Health for access to disclosure forms completed by the authors of all 26 national action plans for cancer. We compared the information in these forms with information on potential conflicts of interest in the published action plans, the authors' PubMed-indexed articles published during the three years preceding the launch of the action plans, and public records of financial transfers from the pharmaceutical industry during the same period.

We obtained access to disclosure forms for 198/424 authors (47%) of the action plans. Conflicts of interest were reported in 49/198 forms (25%), while 63/424 authors (15%) had reported conflicts of interest in PubMed and 124/424 authors (29%) had registered financial transfers from the pharmaceutical industry. No information on conflicts of interest was provided in 3/26 action plans (12%), while 23/26 (88%) stated that none of the authors had conflicts of interest of significance. One or more authors reported potential conflicts of interest in their disclosure form for 23/26 action plans (89%), and potential conflicts of interest were identified for 24/26 action plans (92%) based on information from PubMed and the pharmaceutical industry database.

There was little agreement between the reporting of conflicts of interest in the action plans, the Norwegian Directorate of Health's disclosure forms and open access databases. The findings are limited by the fact that disclosure forms were unavailable for 53% of the authors and that the reported conflicts of interest were not subject to a qualitative assessment.