Friday, May 16, 2014

The Iron Triangle and Evidence-based Medicine

From the Journal of Evaluation in Clinical Practice:
It is naïve to think that we can prevent vested interests from introducing bias. Politicians cannot tally their votes and in sport we rely on umpires, not player, to call the penalties. What are we thinking relying on industry provide evidence about health interventions that they have developed, believe in and stand to profit from? We need to recognize this inherent bias and take action against it.

It is beyond the scope of this paper to discuss practical solutions in great detail, however, we make the following suggestions:

  1. The sensible campaign to formalize and enforce measure sensuring the registration and reporting of all clinical trials (see http:// should be supported – otherwise trials that do not give the answer industry wants will remain unpublished.
  2. More investment in independent research is required. As we have described, it is a false economy to indirectly finance industry-funded research through the high costs of patented pharmaceuticals.
  3. Independent bodies, informed democratically, need to set research priorities.
  4. Individuals and institutions conducting independent studies should be rewarded by the methodological quality of their studies and not by whether they manage to get a positive result (a ‘negative’ study is as valuable as a ‘positive’ one from a scientific point of view).
  5. Risk of bias assessment instruments susch as the Cochrane risk of bias tool should be amended to include funding source as an independent item.
  6. Evidence-ranking schemes need to be modified to take the evidence about industry bias into account. There are already mechanisms within EBM evidence-ranking schemes to up- or downgrade evidence based on risk of bias. For example, the Grading of Recommendation Assessment, Development and Evaluation (GRADE) system allows for upgrading observational evidence demonstrating large effects, and downgrading randomized trials for failing to adequately conceal allocation (and various other factors). However, currently such schemes are agnostic to the origins of evidence and do not expressly recognize the high risk of bias when the producers of evidence have an invested interest in the results. It would be easy to introduce an evidence quality item based on whether a trial was conducted or funded by a body with a conflict of interest. If so, the evidence could be downgraded. Given the failure of current evidence-ranking schemes to detect and rule out industry-funding bias, this is a necessary step if EBM critical appraisal is to remain credible.
Read the whole thing.


h/t: Ivan Oransky on Twitter

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