Experts say socioeconomic status is a health risk factor just like physical inactivity, smoking and obesity.

Low socioeconomic status is linked to significant reductions in life expectancy and should be considered a major risk factor for ill health and early death in national and global health policies, according to a study of 1.7 million people published by The Lancet.

The study, using data from the UK, France, Switzerland, Portugal, Italy, USA and Australia, is the first to compare the impact of low socioeconomic status with other major risk factors on health, such as physical inactivity, smoking, diabetes, high blood pressure, obesity and high alcohol intake.

Although socioeconomic status is one of the strongest predictors of illness and early death worldwide, it is often overlooked in health policies.

“Reducing poverty, improving education and creating safe home, school and work environments are central to overcoming the impact of socioeconomic deprivation,” said lead author Dr Silvia Stringhini, Lausanne University Hospital, Switzerland.

“By doing this, socioeconomic status could be targeted and improved, leading to better wealth and health for many.”

Researchers compared socioeconomic status against six of the main risk factors defined by the World Health Organisation.

The study included data from 48 studies comprising more than 1.7 million people. It used a person’s job title to estimate their socioeconomic status and looked at whether they died early. The authors acknowledge the limitations of using job title as an indication of socioeconomic status, and set up some controls

When compared with their wealthier counterparts, people with low socioeconomic status were almost 1.5 times (46 per cent) more likely to die before they were 85 years old.

Among people with low socioeconomic status, 15.2 per cent of men and 9.4 per cent of women died before the age of 85, compared with 11.5 per cent of men and 6.8 per cent of women with high socioeconomic status.

The study estimated that low socioeconomic status was associated with reduced life expectancy of 2.1 years, similar to being inactive (2.4 years) high blood pressure, obesity and high alcohol consumption, which are associated with smaller reductions in life expectancy (1.6, 0.7 and 0.5 years, respectively).

The greatest reductions were for smoking and diabetes (4.8 and 3.9 years, respectively). Comparatively, high blood pressure, obesity and high alcohol consumption were associated with smaller reductions in life expectancy (1.6, 0.7 and 0.5 years, respectively) than low socioeconomic status.

“Having low social rank means being powerless to determine your own destiny, deprived of material resources, and limited in the opportunities open to you, which—the authors imply— shapes both your lifestyle and your life chances,” says researcher Dr Martin Tobias.

“Whatever the exact effect and impact of low social rank on the health of individuals and populations might be, the authors’ key message is clear: social rank deserves consideration alongside the established...risk factors.”