The Impact of Devolution on Health : A Synthetic Control Analysis of Greater Manchester in England

Background: The devolution of powers over public services from central to local government can enable policy makers to more closely meet the needs of local populations. However, devolved systems may lack the resources and expertise to efficiently implement change. There is limited evidence on the impact of devolution on health. We evaluated the impact of devolution reforms affecting the organisation of health services and other wider determinants of health in Greater Manchester in England. Methods: We evaluated the impact of devolution on population mortality rates, summarised by life expectancy. We estimated changes in life expectancy in Greater Manchester relative to a counterfactual group from the rest of England, using the generalised synthetic control method. We estimated the impact on the whole population and then stratified by sex, local authority, socio-economic deprivation, and baseline life expectancy. Findings: Between 2016 and 2019, life expectancy in Greater Manchester was 0·196 years (95% CI: 0·182 to 0·210) higher than expected. In the first two years, life expectancy in Greater Manchester was protected from the decline observed in comparable areas. In the longer-term, life expectancy rose faster than in comparable areas. These gains were consistent in nine of the ten local authorities in Greater Manchester, larger for the male population, and concentrated in areas with high income deprivation and low life expectancy prior to devolution. Interpretation: Greater Manchester had better population health than expected following devolution. The benefits of devolution were apparent in the most deprived and poorer health areas, suggesting a narrowing of inequality. These population health improvements were likely due to a coordinated devolution across sectors, affecting wider determinants of health and the organisation of care services. Funding: The research was funded by The Health Foundation.Declaration of Interest: We declare no competing interests