How policy informs the evidence

“Evidence based” thinking can lead to debased policy making

Education and debate p 222

Who would not want health policy to be based on evidence? “Evidence based medicine” and “evidence based policy” have such reassuring and self evidently desirable qualities that it may seem contrary to question their legitimacy in relation to reducing health inequalities. However, these terms are now so familiar that it is easy to forget the important question about what sort of data provide appropriate evidence for particular types of decisions. The sort of evidence gathered on the benefits of interventions aimed at individuals may not help in guiding policies directed towards reducing health inequalities.

In this week's BMJ readers have the opportunity to assess part of the process leading to the recommendations of the Independent Inquiry into Health Inequalities (the Acheson inquiry),1 established in 1997 to help the government formulate policy to reduce health inequalities. The inquiry established an evaluation group to report on the quality of the evidence it used to reach its conclusions and support its recommendations.2 This group critiqued submissions to the inquiry, and a list of its own remedies for health inequalities—their “10 steps to health equality”—was released before the Acheson inquiry had itself reported (see box on bmj.com).3

The evaluation group appears to have applied evidence based principles to its consideration of ways to reduce inequalities in health. Essentially it wanted evidence from controlled intervention studies, and its main evaluation consisted of …