Migration and population health
Migration and health is a huge subject, with an equally enormous associated evidence base.
There is a considerable evidence of the effects of ‘selective migration’ on health. Migration is ‘selective’ in the sense that migrants tend to differ from the general population in a number of ways, and tendency to migrate is influenced by factors such as age, level of education, socioeconomic position and, crucially, health status: migrants tend to be of above average health compared with non-migrants.
As a consequence, illness and mortality rates can fall in places with increasing population size, and rise in places experiencing population loss. However, both the scale at which these processes operate (small neighbourhoods vs much larger areas), and the extent of the impact, are disputed.
Importantly, such migration does not seem to play a major role in either the widening health inequalities observed within Scotland, nor in Scotland’s higher mortality rates compared to the rest of the UK. Similarly, GCPH commissioned research published in 2010 showed that widening inequalities within Glasgow could not be explained by selective migration, while other research has demonstrated that the same is true of the city’s higher mortality rate compared to other parts of Scotland.
Despite this, it is still important to understand migration-related issues in understanding the health profiles of Glasgow and Scotland. Particular aspects of historical migration are part of the story of the city’s high levels of ‘excess mortality’, while other GCPH-led research has shown that greater ethnic diversity in England, and particularly in cities like Manchester – linked to this ‘healthy migrant effect’ – is also relevant to this.
For this, and many other reasons, it is important to understand the changing ethnic composition of Glasgow and Scotland, and its implications for population health: this was the focus for another piece of recent GCPH-led work.