Despite seeking treatment on multiple occasions for a recurring ear infection, a man developed a brain abscess and died.

His death has since become the subject of an investigation by Deputy Health and Disability Commissioner Dr Vanessa Caldwell who has found the Whanganui District Health Board (WDHB) responsible of widespread failure in its service to the man.

In her report, released today, Caldwell said the man, whose name is not provided, sought medical treatment at Whanganui Hospital's Emergency Department (ED) five times over a period of two months in 2019.

But during his visits to ED, clinicians did not undertake adequate investigations to understand the extent of the man's disease, and whether he had developed complications from the otitis media, inflammation of the middle ear, Caldwell has found.

He died three days after his final visit to ED as a result of a brain abscess, which is a rare but known complication of untreated otitis media.

Caldwell described the deceased as a Māori man in his 30s who appeared to have had a history of drug addiction but was otherwise in reasonable health.

Her report said he had died due to a "wholly preventable condition" in spite of his multiple attempts to seek help from the ED.

During those visits, clinicians had omitted to perform a CT head scan and had not followed up on abnormal test results adequately, Caldwell found.

She was also critical of a medical officer's inaction because of an assumption that the man's symptoms were a result of drug intoxication.

Caldwell noted DHBs are responsible for the services provided by their staff and said the clinicians involved in the man's care had neglected to appreciate the significance of his repeated visits to ED.

They had also failed to take into consideration his history of poorly resolving symptoms and the possible presence of complications, she said.

"Given the number of staff involved across multiple presentations, I consider that WDHB must take responsibility at an organisational level for the widespread failure in its service."

The failures had meant diagnosis of complications arising from the man's otitis media was delayed.

In her findings, Caldwell said WDHB failed to provide services to the man with reasonable care and skill and had therefore breached the Code of Health and Disability Services Consumers' Rights.

She recommended WDHB and a medical officer provide a written apology to the man's whānau.

Caldwell made multiple recommendations to WDHB, including review and amendments of its ED on-call policy and processes for recall of patients, protocols for managing suspected drug use, and undertake an audit of positive blood cultures received by the ED to identify whether timely follow-up occurred

She further recommended a medical officer undertake self-directed learning on bias in healthcare and reflect on his care in this case relating to his suspicion of drug use and the appropriate course of action.

Caldwell also referred WDHB to the Director of Proceedings for the purpose of deciding whether any proceedings should be taken and stated that she "had regard to the particular vulnerabilities of the man and to the public interest in improving healthcare outcomes for Māori".