The legislation re inquests in England and Wales is, as one would expect, fiendishly complicated to us laymen, and the Rules and Guidance to Coroners (most of whom, by the way, seem to have started out in medicine and gained legal qualifications later) seem to have undergone much review and amendment in the last decade.
However, I may be able to shed a little more light on what used to be described as "Guidance for Coroners on ... Rule 43: Coroner reports to prevent future deaths." The legislation that included Rule 43 has been superseded by the recent implementation of the Coroners and Justice Act 2009. Here is a relevant extract:
Coroners and Justice Act 2009 (c. 25)
Schedule 5 — Powers of coroners
[Page 147]
Action to prevent other deaths
7 (1) Where—
(a) a senior coroner has been conducting an investigation under this Part
into a person’s death,
(b) anything revealed by the investigation gives rise to a concern that
circumstances creating a risk of other deaths will occur, or will continue to exist, in the future, and
(c) in the coroner’s opinion, action should be taken to prevent the
occurrence or continuation of such circumstances, or to eliminate or
reduce the risk of death created by such circumstances,
the coroner must report the matter to a person who the coroner believes may have power to take such action.
(2) A person to whom a senior coroner makes a report under this paragraph
must give the senior coroner a written response to it.
(3) A copy of a report under this paragraph, and of the response to it, must be sent to the Chief Coroner.
Hope this helps, in addition to the info provided by PN and ORAC above.