A review into the Waikato District Health Board's care of a man who later killed three people and then himself in October last year has been completed, but won't be made public.
Ross Bremner had been a patient at the Henry Rongomau Bennett Centre at Waikato Hospital prior to the deaths.
He fatally stabbed his mother and critically injured his father at their Otorohanga home before going on the run.
The 34-year-old's body and that of two elderly people were discovered at a remote Kawhia property a few days later.
The DHB said it had met with Mr Bremner's families, and those of Maurice O'Donnell and Mona Tuwhangai, to share the findings of the serious event review.
It said the Bremner family has declined a DHB request to release the report and it could not do so because it contains confidential patient information.
The review has been passed to the Coroner, the police and the Ministry of Health.