The number of serious mistakes causing harm to patients reported by NHS staff has fallen significantly over the last four years, despite a rise in the total number of incidents.

Data from the National Reporting and Learning System, which records all safety incidents reported by NHS staff, shows the number of incidents in England where the level of harm to patients was described as severe or moderate fell by more than 20 per cent between quarter two of 2012-13 and quarter four of 2015-16 (see first graph).

This contrasts with Wales, where the number of severe or moderate incidents went in the opposite direction. This has prompted concerns that cases of patients being harmed by mistakes in England are being downgraded or underreported to avoid scrutiny.

However, one trust safety lead told HSJ the range of safety interventions underway in the NHS could mean there are fewer incidents of harm taking place and trusts are learning from the greater number of near misses being reported before more serious harm occurs.

There have been calls for some quality checks to be carried out on the NRLS data to ensure incidents are being properly categorised. NHS Improvement said it was looking to create a new incident system that would better analyse what was reported.

In November 2014, the legal duty of candour was introduced for NHS trusts in England, which requires trusts to tell patients where a mistake which led to moderate or severe harm or death had occurred.

The NRLS data shows there was a downward trend in moderate and severe incidents before the duty of candour legislation came into force but the trend accelerated after that point.

The number of deaths linked to an incident has increased since 2012 and since the duty came into force. A death as a result of a mistake or error would be considerably more difficult to downgrade. Again, in Wales, the data has gone in the opposite direction with the numbers of deaths falling significantly since 2012.

One clinician, who alerted HSJ to the trend, said: “A key element of duty of candour is that patients/carers should be provided with a copy of the investigation outcome. This aspect of the regulation is likely to have resulted in staff or trusts having a greater fear of litigation and/or reputational damage arising from an incident. It is possible that this perceived fear has resulted in attempts to avoid triggering duty of candour by downgrading incidents to low or no harm events.”

They added: “The NHS needs a massive cultural shift to place patient safety at the forefront of care. However, the major hurdle is not those staff on the shop floor, but exists within the trust executive boardrooms and within the national structure of the NHS.”

Peter Walsh, chief executive of the charity Action Against Medical Accidents, said it would be an “absolute disgrace” if incidents were being intentionally downgraded to avoid honesty with patients.

He said: “Work needs to be done to understand what these figures mean. That would have to include some kind of investigation into what incidents were declared moderate or low harm…

“If there is evidence of people being dishonest or gaming the system, the way to deal with that is to tackle the problem and the culture of dishonesty. We need to see the Care Quality Commission enforcing the reporting of duty of candour.”

He added: “What this doesn’t say is that the government was wrong to accept the imperative of openness and honesty with patients and families where they are harmed. Duty of candour was introduced to address a very real problem experienced by thousands of people and shown clearly by events at Mid Staffordshire and other healthcare scandals.”

Nick Woodier, lead for patient safety improvement at Nottingham University Hospitals Trust, said he believed the data was positive.

He said: “By increasing the number of low harm and near miss incidents there is a lot we can learn and it could mean we are preventing more severe harms from happening. There are so many improvement focused interventions going at the moment in areas like sepsis and failure to rescue deteriorating patients, there is no doubt these are interventions that are reducing harm to patients.

“I believe the duty of candour has been a positive thing for the NHS. Healthcare staff want to be open and transparent and I think the duty of candour has enabled them to do that.”

Dr Woodier said he would support checks on the quality of incident data, saying it can be difficult to classify moderate harm incidents. He said: “The data should be explored in more detail. A quality check on the data is very sensible so we know what does it mean, what is it really telling us.”

Celia Ingham Clark, national director of patient safety, said the continuing year on year growth in NRLS incident reporting was providing valuable information for learning at a national level.

She said: “We continue to work with providers to improve the quality of reporting and coding of incidents, particularly around those that resulted in death or severe harm. To further this work, we are in the process of developing a new patient safety incident management system to replace the NRLS. The new system will do more to support better reporting, as well as making the process easier and allowing for improved analysis of incidents, patterns and trends.”

The Department of Health declined to comment.

Explore the data

To examine the individual categories of harm in the chart turn on or off each category by selecting them in the legend beneath the graph. You can choose a single category to display or choose multiple categories to display at the same time.