The first detailed picture of patient safety incidents reveals stark variations in the types of errors occurring at trusts across the country.

Overall, around one in five incidents at mental health trusts involved patients self-harming, but the figures varied from 3 to 92 per cent as a proportion of all incidents.

There were also big differences in the proportion of incidents at mental health trusts involving patient abuse by staff or third parties, which was 4 per cent of the total on average. It accounted for just 0.2 per cent of incidents at Mersey Care trust, but 18 per cent at Berkshire Healthcare foundation trust.

A National Patient Safety Agency spokesman said such cases often involved aggressive behaviour by one patient towards another.

In total, 21 per cent of incidents at mental health trusts were "disruptive, aggressive behaviour", but in several trusts it accounted for over half of cases.

The NPSA hopes NHS organisations will examine the data closely to improve data coding.

At acute trusts, the biggest proportion of incidents involved patient accidents. But many also reported a high percentage of incidents related to infrastructure, including staffing, facilities and environment. At Milton Keynes foundation trust, infrastructure problems were linked to 38 per cent of incidents and at Peterborough and Stamford Hospitals foundation trust the figure was 34 per cent.

Among primary care trusts without inpatient services, the biggest proportion of errors revolved around medication, but all of Newcastle PCT’s 11 incidents involved this, compared with the average of 21 per cent.

Each trust has been given a list of actions to implement based on the data they have submitted.