To characterise the conclusions and production of non-systematic reviews about neuraminidase inhibitors relative to financial competing interests held by the authors.
We searched for articles about neuraminidase inhibitors and influenza (January 2005 to April 2015), identifying non-systematic reviews and grading them according to the favourable/non-favourable presentation of evidence on safety and efficacy. We recorded financial competing interests disclosed in the reviews and from other articles written by their authors. We measured associations between competing interests, author productivity, and conclusions.
Among 213 non-systematic reviews, 138 (65%) presented favourable conclusions. Financial competing interests were identified for 26% (137/532) of authors; 51% (108/213) of reviews were associated with a financial competing interest. Reviews produced exclusively by authors with financial competing interests (33%; 71/213) were more likely to present favourable conclusions than reviews with no competing interests (RR 1.27; 95% CI 1.03-1.55). Authors with financial competing interests published more articles about neuraminidase inhibitors than their counterparts.
Half of non-systematic reviews about neuraminidase inhibitors included an author with a financial competing interest. Reviews produced exclusively by these authors were more likely to present favourable conclusions, and authors with financial competing interests published a greater number of reviews.