Generating evidence on interventions to reduce inequalities in health: the Dutch case.

The aim of this paper is to reflect on the type of evidence that is required to design policy measures and interventions to reduce inequalities in health. This issue will be discussed in the context of the Dutch national research programmes on inequalities in health. The first type of evidence relates to the background of socioeconomic inequalities in health. From a very simple conceptual scheme, four policy options can be derived: (1) reducing inequalities in socioeconomic goods; (2) changing the distribution of specific risk factors across socioeconomic groups; (3) diminishing the effect of health on socioeconomic status; (4) offering extra healthcare for people in lower socioeconomic groups. Whereas the evidence on the background of socioeconomic inequalities in health has increased enormously, there is clearly a lack of evidence on the effectiveness of interventions to tackle inequalities in health, which is the second type of evidence that is required. The Dutch five-year programme, including 12 (quasi) experimental studies on specific interventions in different policy fields, showed that this second type of evidence is more difficult to collect, partly because of the methodological complexity of these studies. The third type of evidence relates to the political feasibility of policy measures. It is not enough to know that a specific determinant of socioeconomic inequalities in health might be effectively addressed by a specific intervention. The political will to implement that intervention is obviously a necessary prerequisite for actually reducing inequalities in health. Within the Dutch research programme, the political feasibility of policy measures was explored during a number of conferences, for several policy fields. The lack of evidence on, in particular, the effectiveness of interventions to reduce inequalities in health is clearly an obstacle to tackling inequalities in health. On the other hand, it should be ensured that the lack of evidence is not used as an excuse for not taking policy measures at all.