The number of patients waiting more than four hours for admission after a decision to admit to accident and emergency has grown nearly tenfold in a decade, new figures show.

Data from NHS England, released yesterday, shows 57,841 patients waited longer than four hours but less than 12 hours in 2006-07, compared to 560,398 in 2016-17.

The numbers of patients waiting more than 12 hours – known as a “trolley wait” – has also risen greatly across the country but this is driven by less than five trusts. The growth in waits more than four hours but under 12 hours is spread more evenly across the acute sector.

Breakdowns by trust only go back to 2011-12 – when 108,000 patients waited more than four hours.

Between 2011-12 and last year, A&E attendances grew from 21.5m to 23.4m.

HSJ analysis shows 13 trusts in this period where there were large increases in patients waiting to be admitted despite a decrease in overall attendance (see table below).

Trusts where A&E attendance fell but waits over four hours/under 12 hours increased between 2011-12 and 2016-17

Trust% fall in attendance, 2011-12 to 2016-17% rise in waits over four hours but under 12 hours, 2011-12 to 2016-17

Pennine Acute Hospitals Trust

-0.079

489

Royal Surrey County Hospital FT

-0.290

Total went from zero to 333

Wrightington, Wigan and Leigh FT

-1.053

364

North Tees and Hartlepool FT

-1.790

2,100

Doncaster and Bassetlaw Teaching Hospitals  FT

-4.155

608

North Bristol Trust

-5.907

512

East Cheshire Trust

-8.274

1,357

University Hospital of South Manchester FT

-8.865

256

Croydon Health Services Trust

-9.095

35

Bolton FT

-21.661

389

East Sussex Healthcare Trust

-24.321

316

Harrogate and District FT

-26.283

1,636

Northern Devon Healthcare Trust

-27.437

299

Another trust, Aintree University Hospital FT, saw attendances nearly double between 2011-12 and 2016-17, going from 84,000 to 163,000 – the biggest increase in the country.

Over 2016-17, the trust with the most pressured type one A&E department was Hillingdon Hospitals FT in London, which saw 60.6 per cent of patients within four hours, against the 95 per cent standard.

A spokeswoman for Bolton Foundation Trust said: ”The number of people attending A&E has fallen slightly in the last five years, due to a more efficient GP streaming process and targeted public campaigns around the appropriate use of A&E. However this has meant that many of the people attending our A&E have been extremely unwell and need to be admitted to hospital. This has resulted in an increase in the amount of people that have had to wait longer to be admitted to a bed.

“The trust has taken a number of actions to address this, including adopting a SAFER system and a programme of work across the health and social care economy to identify how we can improve our discharge process.”

East Cheshire Trust said in a statement: ”The department has experienced higher numbers of elderly patients with more complex clinical conditions, in line with the national picture”.

Two trusts, Harrogate and Northern Devon, contacted HSJ after this piece went to press and said their attendaces had dropped because they were no longer responsible for some minor injury units.

Andy Ibbs, director of operations and strategy at Northern Devon Healthcare Trust, said: ”Comparing the last six months of 2016-17 with the last six months of 2011-12, there were 27,000 fewer type-three (MIU) attendances (23,680 v. 50,958), explained entirely by the transfer of these MIUs in October 2016. We did not have a single breach in our MIUs in 2016-17 – breaches occur in the more acute type-one setting (the emergency department). Therefore the transfer of these MIUs to other providers had a disproportionate impact on our all types performance.

“Again comparing the last six months of 2016-17 with the last six months of 2011-12, we saw a 14.8 per cent rise in type-one attendances, from 18,334 to 21,046.

“Although we saw more breaches in March than we would have liked, overall our performance against the four-hour target in 16-17 was excellent – we were the top provider in England against this target on more than one occasion.”

Commenting on the performance data released last week more generally, Tim Gardner, senior policy fellow at the Health Foundation, said: “More people waited longer to access important areas of NHS care in 2016-17 – for things like admission to hospital from A&E, non-urgent surgery and cancer treatment – than at any time in the last five years.

“However, at the same time, the NHS is treating more people than ever before, including more people within the target waiting times.

“Crucially, for big killers like stroke, heart attack and some cancers, the latest data shows that the quality of care being delivered by the NHS is holding. This may be because it is too early to tell whether the pressures on the NHS are affecting the quality of care delivered. Or it may reflect the incredible hard work of NHS staff to ensure good quality of care is maintained despite tightening resources.”