About the Authors

Atle Fretheim

To whom correspondence should be addressed. E-mail: atle.fretheim@nokc.no

Affiliation Norwegian Knowledge Centre for Health Services, Oslo, Norway

Andrew D Oxman

Affiliation Norwegian Knowledge Centre for Health Services, Oslo, Norway

Kari Håvelsrud

Affiliation Norwegian Knowledge Centre for Health Services, Oslo, Norway

Shaun Treweek

Affiliation Tayside Centre for General Practice, University of Dundee, Dundee, United Kingdom

Doris T Kristoffersen

Affiliation Norwegian Knowledge Centre for Health Services, Oslo, Norway

Arild Bjørndal

Affiliation Norwegian Knowledge Centre for Health Services, Oslo, Norway

Competing Interests

All the authors are, or have been, employed by the Norwegian government, which has a substantial interest in improving professional practice in Norway and in containing the costs of health care. The clinical practice guidelines and the study design have not been endorsed by the government or any other organization and represent the views of the authors. No other competing interests are declared.

Author Contributions

ADO and AB had the original idea for the study and wrote the project proposal. AF was the principle investigator, wrote the first draft of the trial protocol, was responsible for running the trial, and wrote the first draft of this report. KH was instrumental in the management and running of the trial, and participated in the interpretation of data. ST provided important input during the planning phase, and also played a key role in the implementation of the study. DTK arranged the data and performed the statistical analyses. All authors contributed to and approved the final manuscript.