Ambulance crews are particularly at risk

In 2001/2002 there may have been as many as 95,501 reported incidents of violence or aggression against NHS staff, according to a National Audit Office survey.

This would represent a 13% rise from the previous year, which itself was a record.

However, the National Audit Office estimates that the true figure may be 40% higher, as two in five attacks are never reported to bosses.

Ministers say that 50 people have been prosecuted over the past eight months over violent incidents involving NHS staff.

Complex paperwork

The NAO says that one of the main reasons is that staff feel that they will not be fully supported if they make a complaint.

Its report says: "Reasons given by staff for reporting incidents include concern that the incident might be viewed as a reflection of their inability to manage the incident."

We need to correct the historic under reporting by NHS staff of incidents of violent behaviour John Hutton, Health Minister

Another reason might be the complexity of paperwork involved in a complaint.

The government launched a major campaign against violence against NHS staff in 1999, with a "zero-tolerance" scheme which allowed hospitals to withdraw treatment from persistently violent or aggressive patients.

The NAO says that the initiative has undoubtedly had an impact, but that even more could be done.

However, health minister John Hutton said: "The safety of staff working in the NHS is paramount.

"We are already working with the NHS and stakeholders to ensure that violence against staff is stamped out.

"We need to correct the historic under reporting by NHS staff of incidents of violent behaviour."

Violence against NHS staff should be dealt with by the courts in the same way as an attack on a police officer Spokesman, Unison

While the majority of nurses are now trained in how to deal with violent patients during the induction process, fewer than half of all new doctors receive such training.

The report mentioned a Nursing Times survey in April 2002 which found that, of 581 nurses assaulted at work, only 11% were offered any form of counselling, despite Department of Health guidance to trusts that counselling should be provided in such circumstances.

A spokesman for the health service union Unison told BBC News Online that it was hoping that courts and police would take a tougher line on those who attacked NHS staff at work.

She said: "Violence against NHS staff should be dealt with by the courts in the same way as an attack on a police officer.

"Things have improved over the years, but some people are still afraid that even if they do report someone, nothing will happen."

The government has set its own target of a reduction in violent incidents of 30% by 2003.