Those who leave school early have double the risk of a heart attack, according to a new Australian study.

The research, published in the International Journal for Equity in Health, found those with no education qualifications had more than double the rates of heart attack (150%) relative to those with a university degree.

The risk was around two-thirds (70%) higher for those with trade certifications and diplomas. The study classed this level of education as “intermediate”.

Conducted by the Sax Institute, the study followed 267,153 men and women in New South Wales aged over 45, tracking them for at least five years on average.

It investigated links between education and heart disease events, such as a heart attack or stroke. While education was the main measure, the study also compared income levels and postcode.

The study found that variations in heart disease were most obvious between education levels across these groups, even after adjusting for age and gender.

It also showed that middle-aged adults who had not completed high school were 50% more likely to have a first stroke than those with a university degree; those with non-university qualifications were 20% more likely.

Lead author and Research Fellow at the Australian National University, Rosemary Korda, said there was a clear gradient in the data between low, intermediate and high education level groups and rates of heart attack or stroke.

“Our main finding is there is a fairly large discrepancy in the rates of cardiovascular (heart) disease – in particular heart attack and stroke – in those with no educational qualifications versus those with a university degree,” she said.

Heart disease is still the leading cause of death in Australia, accounting for 13% of all deaths in 2013.

Clinical Associate Professor David Sullivan from the University of Sydney, who was not involved in the study, said having local information about important diseases that cause a lot of deaths and disabilities in society was extremely helpful.

“And you really couldn’t get more local information than what’s been reported here,” he said.

Studies looking at associations between socioeconomic status and chronic diseases often take a postcode-based approach. But the Sax Institute research was unique in that it analysed risk among lesser-educated people across suburbs, that include the wealthy and more disadvantaged areas.

“Socioeconomic well-being is a health factor and the education side of things here has really just been a broader indicator of the socioeconomic position of patients,” Sullivan said.

“If there’s an educational hurdle for the people we’re trying to help the most, we’ve got to think about the language in which we write our (health) advice.”

Adjunct Professor of Medicine and Chief Medical Advisor at the Heart Foundation, Garry Jennings, who was not involved in the study, said the findings were particularly relevant with respect to recent revelations about Australia’s disappointing education standards.

“It also points to a need for better and more specific education at every level in the community on the perils of smoking and various other risks that people can avoid as far as their health is concerned,” he said.

“We know from some of our Heart Foundation research that knowledge of the risk factors for heart disease and what people can do to avoid it is also related to education. If you don’t know what to do, you’re less likely to do it.”

Jennings said major risk factors for heart disease were physical inactivity, poor nutrition, diabetes, tobacco smoking, and high blood pressure and cholesterol.

“All of the risk factors are higher in people who have not finished school,” he said.

“Smoking rates are higher, blood pressure rates are higher and we also see more diabetes. Those kind of things are not rocket science but we do find more educated people tend to understand them a little bit better.”

The study is part of the Sax Institute’s 45 and Up Study – that has been following one in every ten men and women aged 45 and over in NSW since to explore how Australians are ageing and using health services.

*This story previously said risk of both heart attack and stroke doubled with lack of education. This has now been corrected to just include heart attack, as the increase of stroke is less.

* The headline and lead have been amended to further clarify the study claims an association between lower education levels and higher heart attack risk, not causation.