Scientists found that poverty and poor education are linked to ill health and early death, and should be considered risk factors for these outcomes.

The research, published in The Lancet and coordinated from Imperial College London, revealed that low socioeconomic status (SES) had almost the same impact on health than smoking or a sedentary lifestyle, and was associated with reduced life expectancy of 2.1 years, similar to being inactive (2.4 years).

SES is a measure of an individual or family's economic and social position in relation to others, based on income, education, and occupation. However, although these factors are already known to affect health, no studies so far have compared the impact of low SES with other major risk factors on health. Health policies often don’t consider risk factors such as poverty and poor education when predicting health outcomes.

Now, Professor Paolo Vineis from the School of Public Health at Imperial College London and colleagues have studied 1.7 million people in the UK, France, Switzerland, Portugal, Italy, USA and Australia. They used a people's job titles to estimate their SES and looked at whether they died early (before age 85.)

They then compared SES against the main risk factors (tobacco use, unhealthy diet, physical inactivity and harmful use of alcohol) as defined by the World Health Organisation in its Global Action Plan for the Prevention and Control of Non-Communicable Diseases. The plan aims to reduce non-communicable diseases by 25% by 2025, but omits SES as a risk factor for these diseases.

The researchers found that, compared to their wealthier counterparts, people with low SES were 46% more likely to die early.

The researchers calculated the number of years of life lost for various factors, and compared this to SES. They found the greatest number of years lost were for smoking and diabetes (life expectancy reduced by 4.8 and 3.9 years, respectively). Comparatively, high blood pressure, obesity and high alcohol consumption were associated with fewer life years lost (1.6, 0.7 and 0.5 years, respectively) than low SES.

Based on these results, the authors say that low SES should be targeted alongside conventional health risk factors as part of national and global health strategies to help reduce early death.

Senior author Professor Vineis, who leads the EU LIFEPATH consortium in which this study is embedded, said: “Factors linked to socioeconomic status, such as poverty and poor education, are hugely important in predicting health outcomes. Indeed, our study shows that low SES is just as important as tobacco use, unhealthy diet, physical inactivity and harmful use of alcohol. As a result, we argue that low SES should be included in health policies alongside the other factors.” Professor Vineis also said: “In this study, we measured SES by occupation, so the next step from here will be to reproduce the findings using more varied measures of SES.”

Lead author Dr Silvia Stringhini, from Lausanne University Hospital in Switzerland, said: “Given the huge impact of socioeconomic status on health, it’s vital that governments accept it as a major risk factor and stop excluding it from health policy. Reducing poverty, improving education and creating safe home, school and work environments are central to overcoming the impact of socioeconomic deprivation. By doing this, socioeconomic status could be targeted and improved, leading to better wealth and health for many.”

The study was funded by the European Commission, Swiss State Secretariat for Education, Swiss National Science Foundation, the UK’s Medical Research Council, NordForsk and the Portuguese Foundation for Science and Technology.

“Socioeconomic status and the 25 × 25 risk factors as determinants of premature mortality: a multicohort study and meta-analysis of 1.7 million men and women” by Paolo Vineis et al., published in The Lancet, Tuesday 31 January, 2016.