The original vision of The National Programme for IT (NPfIT) is still achievable despite serious delays to some parts of the scheme, according to a report by the National Audit Office (NAO) released today.

The N3 broadband network and data spine, which together form the infrastructure of the programme, have been deployed on schedule while the Choose and Book appointment booking service, a PACS digital x-ray scheme and an electronic prescription service have also hit deadlines.

But the Summary Care Records scheme – one of the largest parts of the programme – is seriously delayed and is unlikely to be deployed before 2014, four years later than originally planned.

This should become a priority for Connecting for Health – the agency which runs the scheme - according to Tim Burr, head of the NAO.

"The scale of the challenge involved in delivering the NPfIT has proved to be far greater than envisaged at the start, with serious delays in delivering the new care records systems," he said.

"The priority now is to finish developing and deploying these systems."

Planned 'go live' dates were missed for many of the first trusts to take the new care records systems.

Delays with the Lorenzo patient software from supplier iSoft – to be used in the North, Midlands and East – are causing particular problems, while there have also been problems with Cerner's Millennium patient software.

Software development is taking much longer than originally planned, with the first release now expected to be available for deployment at three early-adopter trusts this summer.

In the interim, local service providers have upgraded an existing care records system to fill the gap and the scheme has also been hampered by security concerns.

Strategic Health Authorities are conducting a detailed review of all aspects of data security across their parts of the NHS.

A recent independent report on the Summary Care Records system by University College London recommended that the consent model be changed, and Connecting for Health is considering this possibility, a move welcomed by the British Medical Association.

"There is much to be done to inform the public about electronic patient records. The adoption of a consent-to-view system could go some way to improving the public awareness of electronic patient records," said Dr Chaand Nagpaul, GP negotiator with responsibility for IT in the BMA.

A consent-to-view model would mean patients give consent for their medical records to be viewed on a case-by-case basis rather than giving blanket authorisation – a system already used in Wales.

The programme has also had problems informing staff as well as patients and problems with clinical engagement have led to many staff being wary of new systems.

The report found that in the past two years Connecting for Health has taken steps to strengthen its mechanisms for clinical engagement, including appointing a chief clinical officer to enhance clinical leadership of the programme, but there is still progress to be made before all staff are on side.

Edward Leigh MP, chairman of the Committee of Public Accounts, said commitment from NHS staff is central to the success of the scheme.

"Much more work needs to be done in convincing NHS staff of the benefits that should arise from a fully functioning system," he said.

The Department of Health said it regrets that the care records service is taking longer than was expected.

"We have said before that this is because of a mixture of technical complexity and to allow further time for consultation and the development of the Care Record Guarantee, to meet the concerns that patients may otherwise have felt about the confidentiality of their records," it said in a statement.

The report also found that the NPfIT's costs have risen from £12.4bn to £12.7bn, mainly because of contract resets.