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Complications: tracking down the data on oseltamivir

BMJ 2009; 339 doi: (Published 08 December 2009) Cite this as: BMJ 2009;339:b5387

This article has a correction. Please see:

  1. Deborah Cohen, BMJ
  1. dcohen{at}

    A Cochrane group’s attempt to reproduce an analysis underpinning the use of oseltamivir in pandemic influenza hit a brick wall. Deborah Cohen retraces its steps

    It started this July with an inquiry from a Japanese paediatrician, Keiji Hayashi, to the Cochrane Collaboration about its 2008 review of the treatment of influenza with oseltamivir.

    “You described that oseltamivir 150 mg daily prevented lower respiratory tract complications,” commented Dr Hayashi. “However, we have found that this conclusion is based on the other review by Kaiser and colleagues1 and not on your own data analysis.”

    Hayashi suspected that Kaiser’s conclusion about complications was mainly determined by data from eight unpublished randomised controlled trials (box 1).

    Box 1: Hayashi’s criticism of previous review

    “We have some questions on the conclusion in your Oseltamivir review especially about the prevention of complication (sic). You described that Oseltamivir 150 mg daily prevented lower respiratory tract complications (OR 0.32, 95% CI 0.18 to 0.57) in abstract.

    However, we have found that this conclusion is based on the other review (Kaiser, 2003) and not on your own data analysis. The authors of the review were four employees of F. Hoffman-La Roche Ltd, one paid consultant to F. Hoffman-La Roche Ltd and Kaiser. We cannot find any raw data about this conclusion from your review.

    Kaiser’s review included 10 RCTs; two RCTs (Nicholson, 2000 and T Treanor, 2000) were published as articles in the peer-reviewed medical journal (JAMA and Lancet), but other 8 RCTs were proceedings of congress (5 RCTs), abstracts of the congress (one RCT) and meeting (one RCT) and data on file, Hoffmann-La Roche, Inc, Nutley, NJ (one RCT).

    [There was no significant difference in lower respiratory tract complication rates] between Oseltamivir and placebo, and their Odds Ratios (ORs) were 1.81. But ORs of other 8 RCTs were 4.37.

    We strongly suppose that the …

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