Does industry sponsorship of research affect use of subgroup analyis

January 01, 0001

Does industry sponsorship of research affect use of subgroup analyis

The pharmaceutical industry’s funding of research studies can be double edged sword in that it may help important research studies to be done but also can create a taint regarding interpretation of the data. This international group of researchers performed a systematic review of randomized controlled trials using Medline looking at the effect of industry funding specifically on whether of not the studies reported subgroup analyses.

The researchers report: "469 randomised controlled trials were included, of which 207 (44%) reported subgroup analyses. High impact journals (adjusted odds ratio 2.64), non-surgical (versus surgical) trials (2.10), and larger sample size (3.38) were associated with more frequent reporting of subgroup analyses. The strength of association between trial funding and reporting of subgroups differed in trials with and without statistically significant primary outcomes. In trials without statistically significant results for the primary outcome, industry funded trials were more likely to report subgroup analyses (2.29) than non-industry funded trials. This was not true for trials with a statistically significant primary outcome (0.79). Industry funded trials were associated with less frequent prespecification of subgroup hypotheses (31.3% v 38.0%, adjusted odds ratio 0.49), and less use of the interaction test for analyses of subgroup effects (41.4% v 49.1%, 0.52) than non-industry funded trials."

The researchers concluded: "Industry funded randomised controlled trials, in the absence of statistically significant primary outcomes, are more likely to report subgroup analyses than non-industry funded trials. Industry funded trials less frequently prespecify subgroup hypotheses and less frequently test for interaction than non-industry funded trials. Subgroup analyses from industry funded trials with negative results for the primary outcome should be viewed with caution."

One should perhaps be more skeptical of subgroup analyses when industry sponsored trials have a negative primary outcome

For the full abstract, click here.

BMJ 342:d1569, 28 March 2011
© 2011 BMJ Publishing Group Ltd.
The influence of study characteristics on reporting of subgroup analyses in randomised controlled trials: systematic review. Xin Sun, Matthias Briel, Jason W Busse, et al. Correspondence to G H Guyatt: [email protected]

Category: A. General/Unspecified. Keywords: subgroup analysis, randomized controlled trials, industry, pharmaceutical, funding, systematic review, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 15 April 2011

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