Linking scientific evidence and decision making : A case study of hand hygiene interventions

We consider how data from scientific research should be used for decision making in health services. Whether a hand hygiene intervention to reduce risk of nosocomial infection should be widely adopted is the case study. Improving hand hygiene has been described as the most important measure to prevent nosocomial infection. 1 Transmission of microorganisms is reduced, and fewer infections arise, which leads to a reduction in mortality2 and cost savings.3 Implementing a hand hygiene program is itself costly, so the extra investment should be tested for cost-effectiveness.4,5 The first part of our commentary is about cost-effectiveness models and how they inform decision making for health services. The second part is about how data on the effectiveness of hand hygiene programs arising from scientific studies are used, and 2 points are made: the threshold for statistical inference of .05 used to judge effectiveness studies is not important for decision making,6,7 and potentially valuable evidence about effectiveness might be excluded by decision makers because it is deemed low quality.8 The ideas put forward will help researchers and health services decision makers to appraise scientific evidence in a more powerful way.