Evidence based policy or policy based evidence?

Willingness to take action influences the view of the evidence—look at alcohol

What should we do about alcohol? It is a major threat to the health of the public. Alcohol consumption in Britain has risen by more than 50% in the last 30 years, and alcohol associated deaths, particularly liver cirrhosis, have risen as a result.1 Alcohol is, in addition, responsible for much morbidity, crime, family disruption, and harm to children. A simple prescription would be to review the scientific evidence of what would make a difference, formulate policies, and implement them—evidence based policy making. Unfortunately this simple prescription, applied to real life, is simplistic. The relation between science and policy is more complicated. Scientific findings do not fall on blank minds that get made up as a result. Science engages with busy minds that have strong views about how things are and ought to be.

In the 1980s when debates about fatty diets and heart disease risk were raging, I was struck that individual scientists seemed to have taken entrenched positions on the issue. One new piece of evidence would be even more reason for one camp to call for action to change the nation's diet; but, for the other …