Twenty one patients died in six months while in the care of the mental health trust that serves Brighton and Hove, according to an official watchdog.
The National Patient Safety Agency published the figures which were reported to it by Sussex Partnership NHS Foundation Trust.
The deaths were not necessarily attributable to the trust which provides specialist mental health, substance misuse, learning disability and prison healthcare services.
The trust reported 1,656 safety incidents overall in the six months to the end of September last year, the latest period for which figures have been published.
Most of them – 1,100 incidents – resulted in no harm. Of the rest, 502 resulted in a low degree of harm, 32 in a moderate degree of harm, 1 resulted in serious harm and in 21 cases the patient died.
More than a dozen mental health trusts round the country reported more safety incidents in which patients had died over the same period.
Brighton and Sussex University Hospitals NHS Trust, which runs the Royal Sussex County Hospital, reported 3,250 safety incidents, with 2,844 resulting in no harm.
Of the rest, 351 resulted in a low degree of harm, 47 in a moderate degree of harm, 1 resulted in severe harm and in 7 cases the patient died.
The statistics indicated that safety incidents affected 5.84 patients out of every 100 admitted by the trust – a lower rate than many other trusts that run teaching hospitals.
South East Coast Ambulance Service, which serves Brighton and Hove, reported 237 safety incidents of which 164 resulted in no harm.
Of the rest, 60 resulted in a low degree of harm, 12 in a moderate degree of harm, none resulted in severe harm and in 1 case the patient died.
The definition of a safety incident is broad and covers issues around communication with patients as well as slips and falls, prescribing or administering the wrong medicine and mistakes during operations.
Patients harming themselves, suffering bed sores or other pressure sores or becoming infected with hospital superbugs such as MRSA are also captured in the data.
