A workshop in Stockholm on grading evidence regarding public health interventions

Last Wednesday, the Swedish National Institute of Public Health organised a meeting in Stockholm to explore the do's and don't's of grading evidence regarding public health interventions to help policy makers to identify the best and most effective interventions to promote population health. In public health and health promotion the cry for better evidence-based practice is strong and obvious. However, grading the evidence in public health is more complicated as compared to medical interventions. In public health, interventions are, for example, often group or population based rather than aimed at individuals, effects are often only to be observed in the long run, and interventions are mostly complex, multi-component and context dependent. These characteristics make it more difficult to study public health interventions in research designs that are regarded as the most internally valid, i.e. randomised controlled trials (RCT). In existing systems to grade evidence for medical interventions, such as the GRADE system, evidence not based on RCT designed studies can never be strong, thus favouring individual medical interventions above population-based public health interventions. Therefore, maybe new or other systems need to be developed, or the GRADE system may need to be adapted to better accomodate public health and health promotion interventions. At the workshop I presented the Dutch acknowledgement system for health promotion interventions, led by the the Centres for Healthy Living and Youth Health of the Netherlands National Institute for Public Health and the Environment and the Netherlands Youth Institute. This system was specifically designed  and developed and is being implemented aiming to provide policy makers and professionals with more information on the quality and effectiveness of

available health promotion interventions and to promote use of good-practice and evidence-based interventions by health promotion organizations.  Four levels of recognition are distinguished inspired by the UK Medical Research Council’s evaluation framework for complex interventions to improve health: (i) theoretically sound, (ii) probable effectiveness, (iii) established effectiveness, and (iv) established cost effectiveness. Specific criteria have been set for each level of recognition, taking into account the specific evaluation researhc challenges for public health and health promotion evaluation research. The way the Ducth system works and the first experiences and results were published in a paper in Health Education Research.