It is hoped a new report on why patients die around the time of having surgery will lower the mortality rate for people who go under the knife.
The report, by the Perioperative Mortality Review Committee (POMRC), is the first of its kind in New Zealand and details why between 4000 and 5000 patients a year die in the period around having surgery.
It uses data from between 2005 to 2009 about four procedures: hip and knee arthroplasty (the surgical repair of a joint), colorectal resection (surgery to remove sections of the large intestine), cataract surgery and anaesthesia.
For hip replacement surgery, 0.24 per cent of patients died within 30 days of admission for elective (routine) operations. For patients admitted as an emergency, usually following a hip fracture, 7.3 per cent died within 30 days of surgery.
Falls were the most frequently listed main underlying cause of death in those dying after the surgery.
For elective colorectal resections, 2.1 per cent of patients died within 30 days, while for acute colorectal operations the mortality rate at 30 days was 9.8 per cent.
Malignant neoplasm (abnormal growth) of the colon was the most frequently coded underlying cause of death for those undergoing this procedure.
Of patients admitted for cataract surgery, 0.2 per cent died within 30 days of the operation, with most deaths occurring after the person had been discharged from hospital.
Heart attacks and other types of heart disease were most frequently listed as the cause of death, with other forms of cardiovascular disease also making a significant contribution.
Following 792,614 elective general anaesthetics, there were 177 deaths (0.02 per cent), with just under half due to heart attacks or other cardiovascular causes. Cancers and gastrointestinal diseases also made a significant contribution, the report found.
Outgoing POMRC chairman Iain Martin said that in many cases the operation itself played no part in the patient's death.
"In a small number of cases, however, there are lessons to be learned that can help improve the quality of health care delivery in New Zealand. This report identifies ways to provide information to help health and disability services understand what is happening," he said.
The report recommends mandatory mortality data reporting by all healthcare facilities.
It also suggests the development of a national perioperative mortality review process, and a memorandum of understanding between the POMRC and Coronial Services to ensure access to data.
Australian and New Zealand College of Anaesthetists New Zealand committee chairman Geoff Lang said the report helped identify the factors that could increase risk to patients.
These could be discussed with patients, making their informed consent more meaningful, he said.
"Anaesthetists can also take these risk factors into account when deciding on the appropriate care for individual patients. This will contribute directly to better outcomes for our patients.
"While the report identifies risk factors, at the same time it is reassuring for patients in that its findings also demonstrate that New Zealand has a very high safety record, comparable with other similar countries."
The report was also welcomed by the Royal Australasian College of Surgeons.