Its hard-hitting report, published on Friday, praises NHS England’s handling of the extra numbers but also criticises its failure to put in place enough services outside of hospitals to keep patients healthier.

The watchdog believes this lack of provision underpins its finding that 24% of emergency admissions are avoidable, implying that £3.43bn a year of NHS funds may be being wasted on people who, with better care, would not have ended up falling ill.

GPs offered cash to refer fewer people to hospital
The NAO said: “The impact on hospitals of rising emergency admissions poses a serious challenge to both the service and financial position of the NHS.”

It acknowledged that hospitals have done well to reduce the overall impact of rising emergency admissions in recent years, in particular by reducing patients’ length of stay and treating more patients as day cases.

But it warned: “[The health service] cannot know if its approach is achieving enduring results until it understands whether reported increases in readmissions are a sign that some people admitted as an emergency are being discharged too soon.

“The NHS also still has too many avoidable admissions and too much unexplained variation. A lot of effort is being made and progress can be seen in some areas, but the challenge of managing emergency admissions is far from being under control.”

The NAO cast serious doubt on whether key government-backed NHS initiatives to keep people out of increasingly overloaded hospitals have proved effective. The NHS’s longstanding policy of reducing its supply of beds has made things even more difficult for hospitals trying to deal with rising emergency admissions, the watchdog added.

The latest NHS data published on Thursday on how health services are coping with winter’s intense pressures shows that 95.3% of hospital beds were occupied last week – more than 10% more than the limit considered necessary for patient safety.

The NAO also voiced concern that the number of emergency admissions varies from 73 to 155 per 1,000 overall admissions in different parts of England, suggesting NHS trusts’ admission policies appear to be inconsistent and possibly wasteful.

NHS organisations and health unions endorsed the NAO’s conclusion that health service leaders’ failure to create and deliver more services in and nearer patients’ homes, despite promises to do so, was a key factor behind the upward trend in admissions.

The number of nurses working in NHS community services fell by 15% between 2010 and 2017, the Royal College of Nursing pointed out.

“People, particularly older people, are not getting the support they need in the community, which leads to more emergency admissions and dangerous levels of bed occupancy when demand is high, as we have seen this winter”, said Donna Kinnair, the RCN’s director of nursing, policy and practice.

Saffron Cordery, the deputy chief executive of NHS Providers, which represents hospitals, said proper community services were “central to the [NHS’s] ambitions” to transform the way it cares for patients. However, she added, efforts to do so had been hampered by underfunding and such care not being seen as a priority.

Prof Keith Willett, NHS England’s medical director for acute care, said: “As the report states, there are 12% fewer A&E patients being admitted than was predicted at the start of the decade, and hospitals, community trusts and GPs trialling new models of care have meaningfully reduced admissions compared with their peers.