The situation in NHS accident and emergency wards is "less rosy than it seems", a committee of MPs has concluded.

A report by the Commons public accounts committee welcomed the development of new services designed to take the pressure off A&E wards.

But the committee warned that shortages of specialist staff are hitting the delivery of some services.

Groups such as older people and those with mental health problems were particularly likely to face longer waits, said the report.

Committee chairman Edward Leigh also called for working practices to undergo further modernisation.

There was backing for "innovative" services such as new walk-in centres that cater for minor injuries and illnesses.

But the report found that such developments were largely addressing previously unmet demand rather than taking pressure off existing A&E services.

And the relative cost effectiveness of all emergency care providers has not been established, warned the MPs.

The modernisation of emergency care requires the redesign of work systems around patient needs, they added.

New services

While some "good examples of collaborative projects" were identified, standards should be raised and best practice better shared.

"I welcome the Department of Health's emphasis on providing innovative emergency care services, such as walk-in centres, which are convenient for patients," said Leigh.

"But these new services are not taking the pressure off traditional A&E services, the demand for which continues to grow.

"There has been intense effort by NHS trusts, under the management of the department, to meet the four hour target and patient waiting times in general have been reduced.

"But the picture is less rosy than it seems. Shortages of specialist staff mean that key patient groups, such as older people and patients with mental health problems, are still waiting the longest."

Bottlenecks

Leigh also cautioned that "bottlenecks" in the wider hospital system are still delaying the admission of A&E patients.

"We must have fewer old fashioned practices, such as inefficient bed management and traditional staff schedules built around the convenience of consultants," he said.

"There must also be more integrated working between A&E departments and the other providers of emergency care so that the needs of patients are fully met."

Progress, not perfection

Health minister Rosie Winterton welcomed findings that A&E services have been improving.

"Thanks to our target the number of older people delayed in A&E has almost halved - the sharpest cut in delays for groups admitted to A&E," she said.

"Our drive to eliminate long waits in A&E has made the whole health and social care system work together in new and better ways resulting in faster access to treatment for patients.

"Walk-in centres complement rather than duplicate or replace traditional A&E and GP services offering greater choice. 

"Already six million people have chosen to receive care from the 63 NHS walk-in centres across the country.

"So while we've not achieved perfection yet, we have made huge progress."

Staff shortages

The Liberal Democrats said that there was "still a huge amount to be done to tackle staff shortages" in A&E wards.

"Demand for A&E services is continuing to rise," said health spokesman Paul Burstow.

"There must be much better cooperation between health organisations at a local level so that patients end up getting the right care in the right place at the right time."