Children from poor families are far more likely to end up in hospital A&E departments or need emergency treatment for conditions such as asthma and diabetes, according to shocking figures revealing the consequences of poverty in Britain.

In findings that senior doctors said showed the “devastating impact” of deprivation on child health, the nation’s poorest teenagers were found to be almost 70% more likely to appear in A&E than their less deprived counterparts.

A comprehensive study that examined hundreds of thousands of patient records found inequalities between children from the poorest and richest families were costing the NHS hundreds of millions a year and contributing to pressures on the health system.

Across the 10 most common conditions leading to unplanned hospital visits, the rates of admission were consistently highest among children and young people from the most deprived areas. The study, by the Nuffield Trust, found inequalities in some areas of child health had increased over the last decade in England, despite advances in care.

School-age children from the poorest areas are two and a half times more likely to be admitted to hospital in an emergency for asthma than those in the richest areas. The research shows the gap has grown substantially in a decade.

One of the study’s authors warned that with child poverty increasing, it is “hard to see the inequality gaps we highlight being eradicated any time soon”. Other experts blamed cuts to school nursing and the benefits system as contributing to the divide.

The most deprived young people are 58% more likely to go to A&E than the least deprived groups, with the most deprived teenagers experiencing A&E attendance rates almost 70% higher than those from the best-off families. The most deprived groups were 55% more likely to experience an unplanned hospital admission, though that gap narrowed over the last decade.

Experts said education, diet, environment and the pressures on families living on the breadline meant poor children often ended up in hospital when their health issues could have been headed off earlier. The report’s authors warn that the most vulnerable children are being let down by health services.

In 2005-06, school-age children in the most deprived areas had double the emergency admission rate for asthma compared with their least-deprived counterparts. However, by 2015-16, the gap had grown to about two and a half times. That gap alone is costing the NHS £8.5m per year.

There is also evidence of alarming health inequalities persisting into adulthood. While unplanned admissions for diabetes have been stable or have decreased for younger children, analysts said there had been a “striking growth” for all 20- to 24-year-olds.

The most deprived children were almost twice as likely to experience an unplanned admission in 2015-16 as the least deprived. Reducing these admissions to the level experienced by the least deprived would have led to a decrease of some 244,690 paediatric emergency admissions in 2015-16, and a potential saving of £245m per year.

Nigel Edwards, chief executive of the Nuffield Trust, said: “Asthma and diabetes are both conditions that we should be managing outside hospital. It is an indictment of how we are looking after the most vulnerable in our society that deprived children are now more likely to experience unplanned admissions for asthma than their counterparts did 10 years ago.”

Dougal Hargreaves, Nuffield visiting researcher, said: “Receiving emergency hospital treatment is often absolutely essential, and emergency care saves lives every day. But the level of variation between rich and poor, and the growing inequalities gap in unplanned admissions for asthma, is really worrying.”

Professor Russell Viner, officer for health promotion for the Royal College of Paediatrics and Child Health, said that the report highlighted “the devastating impact poverty can have on child health, especially in relation to emergency admissions for asthma and diabetes.”.

However poverty has an impact on a range of other issues such as education, housing and continuity of healthcare,” he said. “We agree with the authors of this report when they say the most vulnerable children are being let down by health services and we back their calls for policymakers to focus on narrowing the inequalities gap. They can do this by reversing cuts to universal credit which actually leave the majority of families claiming this benefit worse off, and by the restoration of national targets to reduce child poverty, backed by a national child poverty strategy.”

Wendy Preston, head of nursing at the Royal College of Nursing, said asthma should be managed outside hospital. “Yet the worsening shortage of school nurses and health visitors means early warning signs and prevention opportunities are missed, and vulnerable children do not receive the support they need.

The Department of Health said: “Progress has been made in reducing the rate of emergency admissions for the most deprived children – but more needs to be done. To help, we have introduced the world’s first diabetes prevention programme, a new tobacco control plan, targeting the most vulnerable groups, and we are giving local areas £16bn to spend on public health.”