In recent months, there have been high profile stories of how governments can influence public health. The Scottish minimum unit price for alcohol introduced on the 1 May 2018, and more recently the publication of Chapter 2 of the Government’s Childhood Obesity Plan. This update proposed measures to address children’s exposure to junk food advertising on television and online, and called for a ban of price promotions on products that are high in fat, salt or sugar.
20mph zones were shown to increase inequalities in cycle accidents and
rates of death between more and less deprived neighbourhoods
Such policies have great potential to improve public health, by shifting the distribution of health risk and addressing the underlying social, economic and environmental conditions (Hawe and Potvin, 2009)1. However, it is imperative to understand the impact of these policies on health across the entire social gradient. Thereby ensuring the most marginalised, are not adversely effected by policies which aim to improve health overall.
I have been part of a group of academics which recently completed an umbrella systematic review (‘review of reviews’) which aimed to understand the effects of public health policies in high-income countries. You can read about the research in a handy two-page Fuse research brief. As part of the Health inequalities in European welfare states (HiNews) project, we found evidence of 29 reviews (comprising 150 unique primary studies) which detailed the evidence of how fiscal (government revenue), regulatory, education, preventative treatment and screening approaches can be used by governments to influence health inequalities across eight key domains.
|Conceptual framework of population-level preventative public health policies to reduce health inequalities|
Our review highlighted 13 key interventions which were demonstrated to reduce health inequalities. These include taxes on unhealthy food and drinks; food subsidy programmes for low-income families; incentive schemes linked to immunisation status; proof of immunisation for school admission; tobacco advertising control measures; traffic calming measures; oral health (water fluoridation and tooth brushing campaigns); some nutritional and cancer education programmes; universal and targeted vaccinations for indigenous populations; and targeted and population screening interventions.
Worryingly, we also found evidence of interventions that were shown to increase health inequalities – potentially leading to so-called 'intervention generated inequalities’ (Lorenc et al., 2013)2. For instance, lowering alcohol tax by 33% was shown to increase inequalities in rates of death amongst disadvantaged groups in Finland. Environmental interventions, including 20mph and low emission zones, were also shown to increase inequalities in cycle accidents and rates of death between more and less deprived neighbourhoods.
Our research also demonstrates that for some potentially important interventions, such as for policies to control alcohol, there is a lack of robust evaluations highlighting the effects on different groups of people.
Given the volume of literature we found on the effects of government-led policies on health overall, it was disappointing that we could only identify 29 reviews that reported data on health inequalities. Going forward, those tasked with evaluating such policies must report how health outcomes differ for specific interventions by subgroup as standard. Furthermore, reviews should incorporate sufficient information on how the intervention was implemented and enforced to be useful for policy makers thinking of adopting such approaches. We also found many of the reviews and their primary studies were US-based, which could potentially limit the transferability of interventions from one country to another.
Undertaking a systematic review is not without its challenges. When published, the article reads like a definitive narrative when in reality it comprises a multitude of subjectivities – which reviews to include? Which primary studies are relevant? Which outcomes are most appropriate? And how to summarise the state of evidence in a particular field given multiple studies/reviews? The methodology is designed to be systematic, but as it uses human interpretation there is always an element of judgement. Umbrella reviews assess the state of the evidence across a wide area of interest, and are therefore worth the blood, sweat and tears which goes into producing them.
Upstream public health interventions involving state or institutional control offer great hope to improve health for all. However, a comprehensive understanding on the effects of different interventions is a necessary first step to ensure policies have an equitable benefit for all members of society and therefore are worthy tools at the disposal of governments tasked with improving health.
The Health inequalities in European welfare states (HiNews) project is a collaboration between the universities of Newcastle, York, Trondheim, Siegen and Harvard and funded by the New Opportunities for Research Funding Agency Cooperation in Europe (NORFACE).
- Hawe, P., Potvin, L., 2009. What is population health intervention research? 100, I8-I14.
- Lorenc, T., Petticrew, M., Welch, V., Tugwell, P., 2013. What types of interventions generate inequalities? Evidence from systematic reviews. Journal of Epidemiology and Community Health 67, 190-193.
Photo: © Albert Bridge (cc-by-sa/2.0)