Some 300 trusts have yet to comply with at least one alert
Three-quarters of NHS trusts are endangering patients by not complying with safety alerts meant to stop fatal errors recurring, a charity says.
Action Against Medical Accidents found that some 300 trusts had not complied with at least one patient safety alert despite the deadline passing.
AvMA's Chief Executive Peter Walsh said: "Lives are being put at risk."
The Department of Health said it expected all trusts to comply with the alerts and to "record and action them".
It added: "The department will shortly be issuing all NHS organisations a formal reminder of their obligations to do this."
Under the patient safety alert system, the National Patient Safety Agency can issue guidance to NHS organisations to tighten procedures by a set time.
But AvMA said that robust compliance systems were lacking in many hospitals in England.
Figures obtained by the charity via freedom of information requests revealed that 200 trusts had not complied with an alert dating back five years.
Some 80 trusts had not said whether they had complied with 10 or more alerts.
University Hospitals Coventry and Warwickshire NHS Trust had not confirmed whether it had taken action on 37.
The trust told the BBC that three of these alerts were not applicable or could not be carried out for technical reasons. It did concede that they were still working on five but claimed to have fully carried out 41.
In one case, the BBC's File on 4 has discovered evidence that Hinchingbrooke Healthcare NHS Trust, based in Huntingdon, Cambridgeshire, failed to update fully its own policy in the light of advice from the National Patient Safety Agency about the right way to test the position of feeding tubes.
A year later, patient Peter Cameron died a "tortured" death when a nasal-gastric feeding tube was inserted into his lung instead of his stomach, the programme found.
Hinchingbrooke Health Care NHS Trust would not comment in detail on the specific case for legal reasons.
Mr Walsh said he was shocked by the data.
"There is actually no system in place to systematically monitor compliance and follow-up with the trusts," he said.
The Department of Heath said that from April, the Care Quality Commission would have improved powers to monitor incidents and to ensure compliance with alerts.
File on 4 is broadcast on BBC Radio 4 on Tuesday, 16 February , at 2000 GMT, repeated Sunday, 21 February, at 1700 GMT. You can listen via the BBC
or download the