Nearly 6% of patients were waiting four hours or longer in A&D departments during the final quarter of 2012-13, which is the highest level since 2004, The King's Fund has reported.

313,000 patients (5.9%) spent four hours or more in A&E in the period January-March 2013, an increase of more than a third on the previous three months and nearly 40% up over the same quarter in 2011-12, says the health policy think tank, in its latest quarterly monitoring report. 

This means that, across the quarter as a whole, the government's target that no more than 5% of patients should wait longer than four hours in A&E was missed for the first time since Prime Minister David Cameron pledged to keep A&E waiting times low in June 2011, it says.

Nearly 40% of NHS Trusts, or 98, reported breaches of the target, 50% more than in the previous quarter, the data shows. Also, the proportion of patients waiting longer than four hours before being admitted from A&E to hospital - "trolley waits" - rose to almost 7%, also the highest level since 2004. While more recent data shows that A&E and trolley waits have since fallen back to pre-winter levels, this analysis confirms the severe strain on emergency care in early 2013 and the risk that performance could deteriorate again next winter, says the Fund.

The growing pressure on hospitals is also reflected in a survey of NHS finance directors carried out for the report. This suggests that, although the NHS will end 2012-13 in a healthy financial position, the outlook for the next two years is bleak, with the majority expecting the Service to fail to meet its target to deliver £20 billion in productivity improvements by 2015. The main findings from the Fund's survey of 51 finance directors were:

- 90% (46) expect to end the 2012-13 financial year in surplus, with only 4% (2) expecting a deficit;

- more than 40% (21) said that the quality of patient care in their area had got worse over the previous 12 months;

- more than two-thirds (35) indicated that the government's reforms had had a negative impact on performance;

- nearly half (24) had met their productivity target in 2012-13, but less than 40% (19) were confident of doing so in 2013-14, a reduction in confidence compared to previous surveys; and

- more than 90% (49) estimate the risk of the NHS failing to meet its £20 billion productivity target as 50/50 or worse.

This pessimistic outlook reflects growing financial pressure on the NHS, says the Fund. So far, a large proportion of savings have been the result of an ongoing pay freeze for staff, reductions in prices paid to hospitals and cuts in management costs. With these savings increasingly difficult to sustain, further productivity improvements will become harder to deliver without changes to services, and the pressure will be exacerbated by cuts in funding for social care - more than two-thirds of the finance directors (34) identified reductions in local authority funding as affecting their Trust last year.

But despite the pressures in emergency care, other NHS performance measures are continuing to hold up well. Waiting times for referral to treatment in hospital, the number of healthcare-acquired infections and delays in transferring patients out of hospital all remain stable, the Fund reports.

Commenting on these findings, John Appleby, chief economist at The King's Fund, pointed out that "emergency care acts as a barometer for the NHS. The worryingly high number of patients waiting longer than four hours in the last quarter of 2012-13 is a clear warning sign that the health system is under severe strain. The pressures in emergency care will not be relieved by focusing on a single aspect of the problem in isolation - it requires a coordinated response across the whole system."

Mr Appleby added: "while the NHS is in a healthy financial position overall, efficiencies are becoming harder to deliver as one-off savings such as cuts in management costs start to slow. This is compounded by the need to maintain staffing levels following the shocking failures of care highlighted by the Francis report."

"With staff costs making up the bulk of the NHS budget, this will leave little room for manoeuvre - significant changes to services will be required if the NHS is to meet its target of delivering £20 billion in efficiency savings," he said.