Left behind? A longitudinal ecological study of 'regional deprivation amplification' and life expectancy growth in in England (2004 to 2020).

Geographical inequalities in health are substantial and increasing in many countries. In England, there is a life expectancy gap amongst the 20 % most deprived local authorities - between those in the northern regions and those in the rest of the country. We sought to quantify the size and evolution of this gap and to investigate potential contributing factors. We used data from official national statistics covering years 2004-2020 for the 20 % most deprived local authorities in England, divided into north and rest of England. We conducted a Blinder-Oaxaca decomposition which quantified the size of the life expectancy gap for both men and women and identified the key contributing factors drawing on 'deprivation amplification' concept and other theories of health inequalities. We have found that there is a long-standing and widening gap in life expectancy between local authorities in the north and the rest of England. The gap is greater for women than for men (11.7 vs. 7.0 months on average); the widening of the gap over the past two decades has also been greater for women. Our decomposition analysis indicates that regional differences in income are the main contributor to this gap for both men and women (explaining 69 % and 44 % of the gap, respectively), with behavioural factors such as smoking having no explanatory power. Overall, our findings suggest that providing additional income-based resources to areas lagging behind in life expectancy may be an effective way of reducing place-based health inequalities both in England and in similar regionally imbalanced economies.