Dozens of patients at a north London hospital went untreated for at least six months after the hospital introduced IT systems under the NHS's £12.7 billion National Programme for IT, Computer Weekly has learned.
Barnet and Chase Farm Hospitals NHS Trust did not see or treat patients within government-imposed 26 week limits following difficulties with its roll-out of the Cerner Millennium Care Records Service.
The trust was the first in the capital to go live with the system under the National Programme for IT [NPFiT].
Staff at Barnet and Chase Farm Hospitals NHS Trust were unaware of the problem for up to five months. This was because the trust could not produce monthly information on patients who had been waiting too long for treatment following the roll-out.
A trust board paper said: "The introduction of a new Patient Administration System meant the [Barnet and Chase Farm Hospitals NHS] Trust was unable to produce monthly waiting time data between July 2007 and January 2008."
"The production of the waiting time data in February revealed a significant number of waiting time breaches which had occurred there were 63 inpatient breaches."
Barnet and Chase Farm hospitals had 8,500 extra complaints from patients, largely because of delays in making follow-on appoinments after introducing the Cerner Millenium Care Records Service.
The hospital did not re-admit patients whose operations were cancelled at the last minute, within 28 days, as required by government guidelines.
Computer Weekly has learned that a surveillance system - for tracking patients whose operations were cancelled at the last minute by the hospital for non-clinical reasons - was not working in the Cerner Care Records Service.
As a result, at least 18 patients were not re-admitted within a month of the hospital cancelling their operations. The government has set a target that patients should be re-admitted within 28 days of their operations being cancelled.
The trust has sent an explanation of the problems with the patient administration system, and its effect on targets, to the Healthcare Commission, the NHS's regulator.
The trust has also contacted the patients who had been waiting more than 26 weeks. The trust has reported that many of the affected patients have now been treated. And it has given its local primary care trust, at Enfield, an assurance that it now has a system for tracking patients to ensure they are seen within the target waiting times.
Despite the delays in treating patients, Barnet and Chase Farm hospitals had under-used capacity - which is likely to mean under-used operating theatres and wards - in April and May this year, according to a paper to the trust's board last month.
It said: "The ongoing technical patient administration issues have caused problems with scheduling and admission of patients. In April and May the Trust had unutilised capacity arising from this issue."
Implementations in London and the south of England of the US Cerner system - which is only partially modified for use in the UK - has caused disruption at several trusts including the Royal Free at Hampstead, Barts, where some cancer appointments were delayed.
Geoff Martin of London Health Emergency, a group which campaigns on NHS matters, said: "You cannot have operations cancelled at the last minute in these kinds of numbers."
Richard Harrison, Consultant Gastro-intestinal Surgeon and Medical Director at Barnet and Chase Farm Hopsitals NHS Trust said: "You can test the system but you will only find out some of the complexities of operating it when you put it into real life."
Barnet and Chase Farm executives say the Cerner system requires staff to change the way they work. They said they have found it can take much longer to do things that were straightforward before.
There have also been problems with the system. They said many of the problems have been solved and extra staff have been brought in which has helped to ensure that processes run quicker.
NHS Connecting for Health which runs part of the NPfIT said: "Teething problems are to be expected. However, it is clear that the patients and clinicians are beginning to see the potential benefits of the system."
Some officials will regard the patients affected at Barnet and Chase Farm Hospitals NHS Trust as the unfortunate few victims of an IT-based strategy which will eventually help to improve safety, care and health. But others will say that the Department of Health should not embark on go-lives when they know there is a likelihood the health of some patients could suffer as a result.