Heroes Not Zombies

Evidence Based Medicine has three principles – consider the evidence for an intervention; consider the relevance of this evidence for this particular patient based on clinical experience and; thirdly, in consultation with the patient respecting their values and perspectives – to draw up a therapeutic plan. That first part about the evidence base is weakened if the evidence itself is distorted. There are a number of ways to distort it.

One is to spin the findings, as was highlighted in this research –

Previous studies have shown that randomised controlled trials with financial ties to single drug companies are more likely to have results and conclusions that favour the sponsor’s products, and a recent study suggests that the same holds true for meta-analyses.

So researchers in the US set out to determine whether financial ties with single drug companies are associated with favourable results or conclusions in meta-analyses on blood pressure lowering (antihypertensive) therapies.

A total of 124 meta-analyses were included in the study, 49 (40%) of which had single drug company financial ties. Differences in study design and quality were measured.

Meta-analyses with single drug company financial ties were not associated with favourable results but were significantly more likely to have favourable conclusions, even when differences in study quality were taken into account.

In fact, the data show that studies funded by a single drug company have a 55% rate of favourable results that is transformed into a 92% rate for favourable conclusions, representing a 37% gap. The gap shrinks to 21% (57% to 79%) when two or more drug companies provide support. Yet the gap vanishes entirely for studies done by non-profit institutions alone or even in conjunction with drug companies.

These findings suggest a disconnect between the data that underlie the results and the interpretation or “spin” of these data that constitutes the conclusions, say the authors.

Another method is not to publish negative trial findings. Bayer, has just suspended one of its drugs because a trial showed it carried a higher risk of death.

The BART study was the latest in a series of worries about Trasylol’s safety in past years. In 2006 a study published in the New England Journal of Medicine showed increased risks of kidney failure, heart attack, and stroke (2006;354:353-65).

As a result, safety warnings for Trasylol were strengthened in 2006, and approval for use was limited to patients who were having heart bypass graft surgery and were at increased risk of blood loss and blood transfusion during the operation.

In October 2006 international drug regulators’ worries heightened when it became known that Bayer had failed to disclose to the agencies or their advisory panels the results of an unpublished study that had been sponsored by Bayer. Indeed, Bayer scientists had defended Trasylol at an FDA panel hearing but had not mentioned their own study.

Bayer announced that it regretted the mistake and that according to an internal investigation the findings of the trial had been withheld by two Bayer employees and not been passed on as necessary.

Evidence Based Medicine only works well for patients if it is applied in full, and the issue of pharmaceutical company influence on what becomes known and how it is presented required constant vigilance. The more we can have non-drug company funded experts involved in careful peer review the better.