A hospice, the New Zealand Defence Force and a breast screening unit all had adverse medical events in the last year but most were in hospitals run by District Health Boards.
A total of 525 adverse events were reported to the commission by District Health Boards in the year to June 30, 2015 and 67 by other providers.
A report by the Health Quality and Safety Commission released today gives the example of a 78-year-old woman who died after an elective surgery, saying the importance of a slight change in her blood pressure was not appreciated as she was transferred around a hospital.
"Deterioration can happen at any time in a patient's illness, but patients are especially vulnerable after surgery and when they are recovering from a very serious illness," commission chair, Professor Alan Merry, says.
"Recognising and responding to this deterioration quickly is important to avoid cardiac arrest or admission to an intensive care unit."
But falls were again by far the most common adverse event, with 277 cases, and of those who fell 84 broke their hip.
There were 205 cases of clinical management incidents, including those relating to delays in treatment, assessment, diagnosis, observation and monitoring, including patient deterioration.
There were 23 cases of mistakes with medications.
Of the 67 adverse events reported to the commission by other providers, 43 were from the New Zealand Private Surgical Hospitals Association, nine were from ambulance services and 15 were from other providers.
A breakdown of other providers showed five events, all relating to serious harm from falls, in aged-care facilities and four at primary health organisations.
One hospice reported a case of serious harm from a fall, a disability services provider had one event relating to clinical management, NZDF had one event relating to clinical management and a breast screening unit had one event relating to documentation.
The total number of adverse events has risen from 181 in 2006/07 when numbers were first recorded but the commission says reporting has improved.
A common theme in reports on adverse events is communication failure.
Others are policies and procedures, and training and education.
Communication recommendations focused on the development of written materials and more effective patient and family/whanau communication with decisions recorded better in patient notes.