Our study illustrates positive health trends – shown by rises in life expectancy in Scotland and in Glasgow over the last two decades – but also highlights clear concerns in relation to health inequality. Over a period when Glasgow’s population has started to rise and has become more ethnically diverse, and deprivation has reduced marginally, the wide health gap between people living in the most and least deprived parts of Glasgow has not narrowed, and worryingly for women, that gap has widened further.

We already know that Glaswegians die younger than expected when poverty and deprivation are taken into account – and that this "excess mortality" is due to a range of causes: alcohol, drugs, suicides, cancer and circulatory conditions. But what should we be doing to reduce these stark health inequalities? We need to focus on the root causes. Health inequalities are intrinsically linked with social inequalities: in household income, life circumstances, education and opportunity. To address these, no one policy or action is sufficient. Multiple actions at national and local levels are needed. A recent review of health inequalities policy by NHS Health Scotland highlighted that actions were required to address the fundamental drivers of social inequality (imbalances in the distribution of power, money and resources), wider environmental influences (such as the availability of good work, housing and education) and individual experiences (such as providing a nurturing family and educational environment in childhood).

National governments have a vital role in taking action to address the drivers of social inequality. Much of what can be done lies within the remit and power of national governments. To be effective, a policy or action needs to impact across the whole population and to be proportionate to need. Examples would include redistributive fiscal policy (e.g. progressive systems to tax income and wealth), a national living wage and provision of adequate welfare support in proportion to need.

There are other examples of legislative population-wide approaches for specific issues. The ban on smoking in public places has been successful in reducing smoking and exposure to second hand smoke, while the Scottish Government’s proposed legislation to introduce a minimum unit price for alcohol (if it becomes law) would be expected to reduce alcohol harm overall, and also proportionately, with the greatest impact likely in the most disadvantaged communities that are most impacted by alcohol harm.

Policies at a more local level are also needed. Examples include support for living wage employment, income maximisation initiatives, poverty-proofing, proportional targeting of services, investment in housing and regeneration strategies and targeted improvement of the built and natural environment. Many of these approaches are being taken already – for example, Glasgow’s living wage campaign, regeneration activities and the Healthier, Wealthier Children project which helped young families in vulnerable circumstances to maximise their income.

Working at the individual level is also important. Getting It Right For Every Child (GIRFEC) will be enshrined in law later this year, making child rights and child development a much clearer priority in Scotland. Preventive investment as early as possible in childhood provides the best social, health and educational returns while better use of data can help to identify problems and vulnerabilities at any early stage in a child’s life.

However making progress on this and other promising nurture-based initiatives will be challenging in the current context in which, in Glasgow for example, a third of children are living in poverty and levels of child poverty are predicted to rise – in part as a consequence of current and proposed welfare reform policies. Related to this, around half of the population living in poverty in Scotland come from households where at least one adult is working.

Action at the national, local and individual level will not be sufficient without action to address the fundamental causes of inequality – the gap between rich and poor in society on the root causes of inequality.

We know that health and social problems are more common in (developed) countries with greater income inequality and we know that the UK is a country with relatively high levels of income inequality. As others researchers have pointed out, reducing inequality in society is the most effective way of addressing inequalities in health or in educational attainment at school. We need to act now to reduce socioeconomic inequality, while at the same time working to mitigate the health and social impacts of existing inequality.