An 87-year-old man with dementia left the Waitemata District Health Board when he was not being properly monitored and suffered a brain injury and later died.
The board and a public hospital nurse who cared for the man in 2012 breached the code of patients' rights, Deputy Health and Disability Commissioner Theo Baker says in a report made public this afternoon.
Ms Baker asked the board and the unnamed nurse to apologise to the man's family.
He had been suffering from worsening dementia and was admitted to hospital, where he had a fall. Neurological observations were done after the fall but then stopped, despite the DHB's policy of ongoing observations.
His mental state deteriortated and he was later placed on observations every 15 minutes due to his disruptive behaviour and wandering.
Two days later the nurse caring for him failed to do a number of the required 15-minute checks and made an inadequate hand-over of the case to another nurse before taking a meal break.
When he returned from his meal break, the nurse realised the patient was missing. When security was contacted it was found he had left the ward about two hours earlier.
A member of the public found the man at a bus stop and called an ambulance. He was returned to hospital, where he was found to have a large subdural haematoma - a bleed between the brain and its covering tissue, indicating a brain injury had occurred - and later died.
Ms Baker said the DHB failed to ensure its staff carried out the required neurological observations following the man's fall and failed to take action as his condition deteriorated. She also criticised the DHB's lack of any formal process for meal-break handover of patients by nurses, that "visual handover" was not required and that there was no structure to ensure appropriate staff were present during meal breaks.
She recommended the DHB review the training of nursing staff in the medical division regarding care of the elderly with dementia, arrange for an audit of documentation practices in the general medical ward and review its handover processes.
The DHB said it accepts the deputy commissioner's findings.
Chief medical officer Dr Andrew Brant said the DHB had apologised to the man's family and recognised the legitimacy of the concerns they had expressed to the HDC.
"Clearly, our management of this patient could have been better and we are genuinely sorry that on this occasion we did not meet the very high standards of care that we strive for," Dr Brant said.
"Caring for dementia patients in an acute setting is very challenging and our staff did the best they could at that time in what was a busy and difficult situation.
"We have learned from the unfortunate chain of events outlined in the HDC report and made some systemic changes as a result. Like all hospitals, we continually adjust and improve our models of care to protect patient safety and to support the best outcomes for our patients.
"We hope that this report also serves as a learning tool for other hospitals who are confronting the reality of caring for dementia patients on their wards."