Poor people are much more likely than wealthy people to die after undergoing emergency surgery, according to new research.

Patients from the most deprived areas have a 29% greater risk of dying than those from the wealthiest districts, the study from University College London found.

Researchers examined the number of people dying within 30 days of having an emergency laparotomy at one of 178 NHS hospitals in England.

Prof Ramani Moonesinghe, a co-author of the findings, said: “We are satisfied we have identified a significant association between patient poverty and the mortality rates following this commonly performed emergency procedure.”

However, she said, there was no data available to indicate the exact reasons for the link. “Possible causes could include lifestyle-related risks, delayed diagnosis or presentation to hospital, along with follow-up access to healthcare services after discharge,” she said.

The conclusions are important because they suggest that someone’s housing, education, employment status and working conditions – not just their medical condition – can influence who is most likely to die.

About 61,000 people a year in the UK have an emergency laparotomy. It involves surgeons making an incision in the abdominal cavity to allow examination of the patients’ internal organs, such as the stomach and small and large intestines. It is classed as high-risk surgery and patients have a risk ranging from 5.4% to 23.9% of dying within 30 days.

The researchers’ findings are published on Tuesday in the British Journal of Anaesthesia. They analysed data relating to 58,790 people who had the procedure between December 2013 and November 2016 and whose details were held by the national emergency laparotomy audit. They found that patients from the poorest socioeconomic backgrounds were in greatly increased danger of dying than those from wealthier ones.

Overall mortality among the wealthiest quintile (fifth) of the population was 9.8% but it rose to 11.2% among those from the most deprived quintile. However, after adjusting for patients’ existing health conditions the researchers found an even greater correlation between deprivation and mortality that meant the worst-off were 29% more likely to die.

John Abercrombie, a consultant emergency surgeon and council member of the Royal College of Surgeons of England, said: “This important study shows that patients from deprived areas have a higher mortality rate from emergency abdominal surgery when compared with those who are better off.

“Survival rates should be consistently high across socio-economic groups. Patients’ chances should not depend on their pocket or their postcode. It is vital that the government ensures timely access to emergency care for patients with serious emergency abdominal conditions. These figures underline the necessity of preventing problems before they occur.”

The most recent edition of the national emergency laparotomy audit, which came out last week, showed that the overall risk of death within 30 days had remained unchanged at 9.6% for the last two years.

The audit, a collaboration between the Royal College of Anaesthetists and the National Institute of Academic Anaesthesia, tracks the outcomes of patients having the operation.

The UCL team also concluded that the variation in patients’ risk of dying was not due to the quality of either the hospital they had their surgery in or the care they received around the time they underwent the operation. In fact many of the poorest patients had their surgery in large teaching hospitals in urban areas, which generally have good standards of care.

The academics also uncovered stark geographic differentials in patients having an emergency laparotomy. While just 7.6% of those who underwent it in south-central England were from the poorest fifth of the population, almost a third of those having it in the north-west came from that group.