In 2004-05, a survey of NHS acute, ambulance and mental health Trusts found
974,000 patient safety incidents (PSI's) were reported.
Hospital acquired infections were estimated to increase the PSI figures by around 300,000 incidents.
It is estimated that about 50% of these incidents are preventable (National
Audit Office 2005:1).
It is estimated from International studies that at least a quarter of these figures may relate to medically negligent PSI's, yet in 2005-06 there were only 5, 697 legal claims (NHSLA 2006) making about 2% of all possible claims.