The number of patients who have been involved in safety incidents while undergoing NHS treatment has risen by 12 per cent in six months.

The National Patient Safety Agency released new figures revealing that 459,500 people were affected between 1 October 2008 and 31 March 2009 in England.

National reporting and learning means that the lessons learnt from safety problems are not trapped within the walls of one facility

The data also showed that 5,700 patients experienced serious harm or died because of mistakes and near misses. The NPSA said the rise was due to improved reporting. Overall, in 303,016 (66 per cent) of the cases no harm came to the patient and in 122,246 (27 per cent) there was low harm.

A further breakdown showed 28,521 (6 per cent) of incidents ended in moderate harm and 5,717 (1 per cent) resulted in severe harm or death.

Thirty two per cent of reports were accidents involving patients that could have been avoided, followed by errors or near misses with treatments or procedures (10.1 per cent) and medication (9.4 per cent).

Reports were provided by 382 out of the 392 health trusts in England. Overall, there has been 3 per cent rise in the number of trusts reporting errors or near misses.

NPSA chief executive Martin Fletcher said: “National reporting and learning means that the lessons learnt from safety problems are not trapped within the walls of one facility but can be spread across the NHS to prevent similar events occurring.”

NHS medical director Sir Bruce Keogh said: “We have learnt from industries such as aviation that scrupulous reporting and analysis of safety related incidents, particularly ‘near misses’, provides an opportunity to reduce the risk of future incidents.”