Hospitals have been hit by recent power outages, highlighting the need for continuity plans

The need for comprehensive business continuity plans has been further underlined after 80 NHS hospital trusts were affected by a computer system failure over the weekend initially caused by power cuts.

Some health staff in the North West and West Midlands were unable to check appointments and access patient details online as a result of the failure.

NHS Connecting for Health (CFH) confirmed in a statement that there had been a "serious interruption" to services provided by the CSC Alliance from its datacentre in Maidstone. "Technical issues following power system interruptions mean that data held on computers in the central "data centre" for the region cannot be accessed," the statement read. "The nature of the incident meant that service could not immediately be provided by the back up systems."

NHS CFH said staff from CSC and subcontractor Hitachi had been "working round the clock" to resolve the problem, but admitted that currently many trusts are "continuing to provide normal service by operating manual contingency systems".

The incident comes days after businesses in central London – including IT Week – were affected by power cuts that caused an estimated £10m in lost earnings.

The events come as a new survey from business communications services provider Viatel reveals 62 percent of UK businesses are vulnerable due to incomplete business continuity plans.

The survey of 100 IT directors found that while 80 percent claimed they had a business continuity plan, 62 percent admitted this did not include the phone system and that they were reliant on employees using mobile phones – even though this made it more difficult for clients to contact them.

The report also found almost a third of respondents were unable to access systems for at least a week after an incident occurs.

Michael Davies product manager at Viatel, said in a statement that the results were "really worrying". "Many businesses are leaving themselves open to considerable loss of business as well as damage to their reputation," he added. "Having a comprehensive business continuity plan in place is no longer an option but a necessity."

However, the survey did uncover one possible reason for the low adoption of comprehensive business continuity plans with almost half of respondents claiming business continuity costs are too high.