The "wide variation" in mortality rates following bowel cancer surgery across the country needs to be investigated, according to top cancer specialists.
The 2019 Bowel Cancer Quality Improvement Report was released on Tuesday and detailed wide variations in the mortality rate of patients following bowel cancer surgery across different District Health Boards (DHB).
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The result of a partnership between Ministry of Health cancer specialists and the National Bowel Cancer Working Group, the report found 7170 people had major surgery for bowel cancer in public hospitals between 2013 and 2016, with four percent dying within 90 days of the surgery.
While mortality rates remained fairly similar each year, ranging from 3.2 percent of patients dying to 4.6 percent, variations in the mortality rate across different DHBs was more concerning.
No one died across the four years within 90 days of the surgery in the Wairarapa, while 7.6 percent died in Whanganui.
"The overall post-operative mortality in patients undergoing surgery is acceptable, but there is currently wide variation between DHBs that needs investigating," the report said.
They called on DHBs that performed well to act as a helpful resource to "support quality improvement programmes" in DHBs with high mortality rates.
Wairarapa was the only DHB without any deaths within 90 days, but it also had one of the lowest numbers of patients having the surgery, with only 44 across the four years.
Of all other DHBs, Auckland had the lowest 90 day mortality rate with 2.2 percent of patients dying, followed by South Canterbury at 2.4 percent.
Auckland had 445 patients and South Canterbury had 168.
After Whanganui, the Lakes DHB in the central North Island had a high mortality rate with 7.4 percent, followed by Taranaki and West Coast with 6.5 percent.
The report also found variation in the 19.6 percent of bowel cancer patients nationally who needed emergency surgery. In the Bay of Plenty, 12.6 percent of patients needed emergency surgery, while it was 31.1 percent in Tairawhiti.
"National initiatives to improve outcomes in patients undergoing emergency surgery and to improve pathways that reduce the rate of emergency surgery are likely to reduce overall post-operative mortality.
"The rate of emergency resections performed for colorectal cancer is high in New Zealand, and may contribute to worse cancer outcomes."