Dear Dr Godlee

In your recent exchange of letters with Professor Sir Michael Rawlins [www.bmj.com/tamiflu/nice], we were surprised by the claim that in our review[1,2] “reviewers’ extraction sheets were filled in by Roche.” We would like to take this opportunity to make it clear that this claim is not true.

During the conduct of health technology assessments we often request additional unpublished data from manufacturers, or from authors of studies that are not industry funded. We tailor any such request according to the data required and aim to make it as clear, concise and straightforward as possible. This improves response rates and we believe makes it more difficult for investigators to sidestep providing the data we require.

In the case of the review of treatments for influenza, we made requests to both GSK and Roche for data that were either missing from the original journal articles, or where publications for a trial could not be identified. As part of the request, a table was provided into which unpublished data for the two main outcomes, could be inserted. These additional forms were not our data extraction sheets.

Data and other information provided by both manufacturers were considered and then the relevant data were taken from the supplementary tables and added to the appropriate data extraction tables by the CRD research team.

If there were such uncertainties regarding the conduct of our review, we would have been more than happy to clarify this if we had been contacted.

CRD is supportive of initiatives that seek to increase access to data from clinical trials and believe that all clinical trials should be registered and published in full. Through PROSPERO the international prospective register of systematic review protocols, we are also committed to increasing transparency and guarding against selective reporting in systematic reviews.

With this in mind, we submit this clarification as an open letter that can be posted on BMJ.com.

With best wishes

Dr Jane Burch
Professor Lesley Stewart
Centre for Reviews and Dissemination

[1] Burch J, Paulden M, Conti S, Stock C, Corbett M, Welton NJ, Ades AE, Sutton A, Cooper N, Elliot AJ, Nicholson K, Duffy S, McKenna C, Stewart L, Westwood M, Palmer S. Antiviral drugs for the treatment of influenza: a systematic review and economic evaluation. Health Technol Assess. 2009;13(58):1-290.

[2] Burch J, Corbett M, Stock C, Nicholson K, Elliot AJ, Duffy S, Westwood M, Palmer S, Stewart L. Prescription of anti-influenza drugs for healthy adults: a systematic review and meta-analysis. Lancet Infect Dis. 2009;9(9):537-45.

Competing interests: None declared