The need for, and value of, a spatial scan statistical tool for tackling social health inequalities.

Today, one important challenge in developed countries is health inequalities. Research conducted in public health policy issues supply little evidence for effective interventions aiming to improve population health and to reduce health inequalities. There is a need for a powerful tool to support priority setting and guide policy makers in their choice of health interventions, and that maximizes social welfare. This paper proposes to divert a spatial tool based on Kulldorff's scan method to investigate social inequalities in health. This commentary argues that this spatial approach can be a useful tool to tackle social inequalities in health by guiding policy makers at three levels: (i) supporting priority setting and planning a targeted intervention; (ii) choosing actions or interventions which will be performed for the whole population, but with a scale and intensity proportionate to need; and (iii) assessing health equity of public interventions.