First do no harm: developing interventions that combat addiction without increasing inequalities

Interventions to combat addiction and related problems, like other public health interventions, have the capacity to increase health inequalities. To combat this, intervention developers should always undertake an analysis of the equity implications of interventions, set interventions in terms of a systems approach that takes account of reciprocal influences between ‘upstream’ and ‘downstream’ approaches, and act as advocates for strategies that address the social causes of inequalities. Throughout England, the life expectancy at birth gap between the 10% most deprived neighbourhoods and the 10% most affluent stands at approximately 9 years for boys and 7 years for girls 1. These inequalities in health are ubiquitous throughout all high-income countries—in the United States, for example, the life expectancy at birth gap between its most and least affluent counties is now more than 20 years 2. Health inequalities exist among almost all causes of morbidity and mortality, ranging from obesity and cardiovascular disease to mental health and most cancers 1. There is also a clear social patterning of addictions with harmful alcohol and tobacco consumption, problematic gambling and drug use higher in lower socio-economic groups and in less affluent neighbourhoods 3. For example, in the United States, smoking rates are almost double among adults living below the poverty line (26%) compared to those living above the poverty line (14%), and throughout Europe binge drinking rates are considerably higher among those with the lowest educational level compared to those with the highest education 4, 5. Addressing these socio-spatial inequalities in health and addictions has been one of the central aims of public health policy, practice and research to a greater or lesser extent, depending on the political mood 1. The causes of these health inequalities are now fairly well understood. In the 40 years since the publication of the (in)famous Black report in the United Kingdom in 1980 (which was the first major piece of policy research internationally to set out the extent of health inequalities in a high-income country) 6, there has been extensive research examining the determinants of these inequalities. A general consensus is now beginning to emerge that they are a product of the complex interaction of material, psychosocial, behavioural and cultural factors experienced, both individually and collectively, and additionally structured by macro-level political and economic arrangements 1. However, it is only recently that our sophisticated understanding of causality has actually been used to develop policies and interventions to address health inequalities explicitly 1, 6. Although the evidence base on how to tackle health inequalities effectively is small and emergent 7, one area of research that is gaining increasing attention is that of intervention-generated inequalities (so-called IGIs) 8. Perhaps the most famous example of this is the Inverse Care Law, whereby the provision of health-care services (including secondary prevention) is greater in areas with lower health need, thereby exacerbating existing inequalities in health 9. This is increasingly the case, as more health services throughout Europe are subject to marketization and privatization 10. Additionally, there is suggestive evidence that IGIs might be a problem in the primary prevention strategies utilized in public health 8. From a health equity perspective this is important, as interventions—however well-intended—which increase inequalities inadvertently could be considered as ‘harmful’, even if they are beneficial to overall population health or reduce addictions within the general population. In the case of behavioural interventions, this may be a result of their reliance upon voluntary engagement with the programmes 8 or because they do not address the wider social and economic factors that also shape socio-economic and spatial health inequalities 1, 11. For example, although the evidence base is still small, international systematic review evidence suggests that media-based mass health promotion campaigns might increase inequalities (particularly in smoking and obesity) 12, 13. In contrast, primary prevention strategies that address the social, rather than simply the behavioural, determinants of health and addictions and which use regulatory (e.g. age restrictions, standardized packaging; fast food marketing restrictions) or fiscal approaches (e.g. tobacco pricing; food subsidy programmes) may have more positive effects among lower socio-economic groups, thereby helping to reduce health inequalities 8, 12, 13. None.