SUPPORT Tools for evidence-informed health Policymaking (STP) 12. Dealing with insufficient evidence

Background: This article is number 12 in a series of 21 articles on tools for evidenceinformed health policymaking and addresses the issue of decision making when there is insufficient evidence. Policymakers often have insufficient evidence to know with certainty what the impacts of a health policy or programme will be. They must still make decisions. Objectives: In this article, we suggest four questions that can be considered when there is insufficient evidence to be confident about the impacts of implementing a policy or programme. Key messages:  If there is insufficient evidence to allow one to be confident about the impacts of implementing a policy or programme, the following questions should be considered: 1. Is there a systematic review of the impacts of the policy or programme? 2. Has inconclusive evidence been misinterpreted as evidence of no effect? 3. Is it possible to be confident about a decision despite a lack of evidence? 4. Is the policy or programme potentially harmful, ineffective or not worth the cost?  Common mistakes that should be avoided include: Making assumptions about the evidence without a systematic review Confusing a lack of evidence with evidence of no effect Assuming that insufficient evidence necessarily implies uncertainty about a decision Assuming that it is politically expedient to feign certainty, and  Saying “no” to a policy or programme, or saying “yes” when there are important uncertainties can have undesirable consequences. Often it would be better to say “only with a well-designed impact evaluation” STP 12 Dealing with insufficient evidence 2009 06 12 2