Objectives: Many initiatives have been taken in European countries that are designed to reduce inequalities in health. However, the effects of only a very few of these initiatives have been assessed. The main aim of a Dutch research and development programme was to systematically investigate and evaluate interventions aimed at reducing inequalities in health. In this paper, we report on this investigation, and draw lessons from the methodology used to evaluate such interventions.
Approach: The programme included 12 evaluation studies, focusing on the wider determinants of inequalities in health (n = 2), behavioural determinants (n = 4), working conditions (n = 3) and health care (n = 3).
Results: An experimental design was applied in two evaluation studies. The studies provided evidence of a positive effect. A quasi-experimental design appeared to be the only attainable option in seven studies. Five of these provided sufficient evidence for a positive effect, but two interventions appeared not to be successful. In three studies, no experimental or quasi-experimental design could be applied.
Conclusions: The programme showed that it is possible to apply experimental or quasi-experimental studies to complex public health interventions. The Programme Committee steering the programme considered that the evidence generated by the experimental and quasi-experimental studies justified the implementation of the interventions on a wider scale, accompanied by further evaluation studies. Further development of the methodology of public health interventions is necessary. These include non-experimental designs such as international comparisons and time trend studies, especially in order to be able to evaluate broader policy measures.