There were 377 public hospital mishaps in the last year resulting in 86 deaths, many of which "should never have happened'', a report has found.
The Serious and Sentinel Events Report, released today, identified events which were life-threatening, led to an unexpected death, or to a major loss of function in of New Zealand's public hospitals between July 1, 2010, and June 30, 2011.
It found that falls were the most common events with 195 incidents recorded, up from 130 the previous year.
A total of 25 medication errors were reported, along with 108 clinical management incidents.
These included delays in responding to a patient's changing or deteriorating condition; poor communication between health professionals; and delayed diagnoses due to failings in referral processes and the reporting of results.
There were also 11 serious wrong site surgery cases in the year. This encompasses surgery performed on the part of the body, the wrong surgical procedure performed, and surgery performed on the wrong patient.
Commission chairman Alan Merry said the people involved in the year's 377 events were let down by a system that existed to protect them.
"We should view these events through the eyes of patients and their families, and acknowledge that many of them should never have happened.''
New Zealand had an excellent health and disability system with more than 2.7 million people treated in public hospitals or as out patients each year and very few coming to serious harm.
"The fact remains, however, that a small number of people are injured in the course of receiving treatment and an even smaller number lose their lives as a result of something that happens to them in hospital,'' Professor Merry said.
"It's not about apportioning blame, it's about improving the quality and safety of our health and disability services.''
The commission was working with the sector to prevent and reduce harm from falls, and on initiatives to reduce medication errors and health care associated infections.
It was also working to promote use of the World Health Organisation's safe surgery checklist, and to improve the quality of data and reporting of adverse events.