Trusts where patient safety incidents are most likely to cause deaths, and those with the highest and lowest reporting rates, are revealed for the first time in an exclusive HSJ analysis.
Figures collated from National Patient Safety Agency organisational reports also reveal it often takes trusts many months - and in one case more than a year - to report incidents, including patient accidents and medication errors.
The analysis comes as Healthcare Commission findings, seen exclusively by HSJ, reveal trust boards are only monitoring safety information such as mortality rates on an "ad hoc" basis.
Of 422 NHS organisations in England and Wales, 45 did not admit to any patient safety incidents or reported too few to be included in the NPSA data. Of the 377 in the agency's sample, the organisation with the lowest reporting rate recorded just 11 incidents from April to September 2008, the first period for which individual trust data has been made available.
The highest reporting rates were at Leicester City primary care trust, which reported 158 incidents per 1,000 bed days, compared with an average of 18 among other PCTs with inpatient services.
NPSA chief executive Martin Fletcher said: "Organisations with a high rate of reporting are usually organisations where there's a strong commitment to patient safety.
"We're trying to encourage trusts to review their own reporting rate."
The time it takes trusts to report incidents ranges from seven days, at Medway foundation trust, to 421 days at Sefton PCT.
Sefton PCT deputy director of corporate performance and standards Jan Snoddon said the PCT had had technical difficulties in submitting data and was revising its processes.
She said: "NHS Sefton takes patient safety extremely seriously. We have a strong reporting culture and are committed to being open and transparent. This is the only way we can continue to learn and improve patient safety."
Information was gathered internally through audits, she said.
Level of harm
The figures also reveal the level of harm resulting from patient safety incidents at each trust.
Overall, two thirds of incidents are reported as causing no harm, 27 per cent as low harm, 6 per cent as moderate, 0.9 per cent as severe and 0.5 per cent as death.
But at Newham University Hospital trust, a third of incidents caused severe harm or death. At other medium-sized acute trusts, such as Luton and Dunstable foundation trust, there were none.
A Newham University Hospital trust spokeswoman said the trust was looking at how patient safety data was classified.
She added: "We have asked the NPSA to help us to identify any anomalies in reporting practice."
NHS medical director sir Bruce Keogh said the NHS "had some work" to do to address employees' fears they would be "treated badly" if they reported an incident, and that it would not lead to changes.
He said: "Patient safety incidents cost the NHS around£2bn a year and cause unnecessary suffering."
A Healthcare Commission report out today, Safe in the Knowledge: How do NHS trust boards ensure safe care for their patients? criticises boards for relying on committees to scrutinise safety information.
Researchers found board members were struggling to fulfil their responsibilities around safety. Most non-executive directors were "passive recipients of information, with limited understanding to effectively challenge it", the report states.
It says hand hygiene, mortality rates, suicides, absconding, violence towards staff and patient slips, trips and falls were only monitored on an "ad hoc" basis.