By David Woods

Nothing is calculated to agitate health economists more than the perception that what you do is somehow inexact, or “soft”. Yet no matter how precise and rigorous the recommendations you make to decision-makers in the pharmaceutical industry, there’s a lingering perception that they’re designed to justify financial preconceptions. So even if your science is not an inexact one, it is one whose findings can be used inexactly. The issue therefore becomes not only what evidence you present – but how you present it.

And today, with closer scrutiny not only of a drug’s efficacy but of its competitive value, healthcare resource allocation decisions must be evidence-based, transparent, credible, and legitimate. But, says Dr Marc Berger, Vice President of Human Health at Merck, rigorous review of evidence, assessment of its quality, and delivery of a useful report is still an evolving skill for many decision makers. Moreover, he says, the most common problem facing decision-makers is lack of high quality evidence.

A report from the Canadian Health Services Research Foundation in May 2005 describes three types of evidence: core scientific evidence, which is close to the truth and replicable; colloquial evidence based largely on case studies and anecdote; and “social science” evidence (including cost-effectiveness analysis (CEA)), which has elements of the first two, plus some opinions thrown in for good measure. These need to be separately considered and made more explicit if they are to appropriately inform healthcare decisions. Certainly, they must be presented clearly and unequivocally.

Dr Kenneth Smith, assistant professor of health policy at Jefferson Medical College , has some straightforward advice about all this for his fellow professionals: “They should assert themselves as scientists with expertise in human behaviour,” he says, “and not be afraid to challenge conventional wisdom.” Moreover, he adds, “economic research should drive marketing; not vice versa.” This argues for bringing economic research much earlier in the drug development process. He sees a need for rigorous application of theory. “Communicating the implications of that – including its nuances– makes health economists better placed to push for better data – which means better evidence,” he says.

In the final analysis though, there will always be a barrier to definitive evidence and consistent and unambiguous policy decisions because of the conflicting priorities of different stakeholders and the different interests within a pluralistic society. The role of experts charged with summarising the evidence is to lower that barrier through clearly defining the types of evidence available, their strengths and limitations, and what assumptions must be applied to make sense of what may not always be totally compelling evidence.