Doctors correctly referred 36 urgent cases with another 12 picked up by the specialist assigned to grade each case based on information in the referral.
A correct referral significantly reduced diagnostic wait times for the most serious cases with a median of 21 days from referral for those 48 patients compared to 67 days for the remaining patients.
The audit found 41 per cent (74 people) had their first test within 30 days while 32 per cent (58 people) had to wait more than 90 days. Of those, more than 30 people waited longer than 120 days.
The study authors said the results confirmed concerns that there were long delays for a significant number of patients between GP referrals and specialist diagnosis in the Bay of Plenty.
"While other DHBs may have their own referral process to ensure the timely diagnosis of colorectal cancer, it is likely that the picture in the Bay of Plenty is not greatly different elsewhere," they wrote.
One of the authors and consultant general surgeon at Whakatane Hospital, Simon Raines, said referrals from GPs containing the correct information were essential for making sure the most urgent cases were addressed quickly.
He said it was difficult for GPs to get it right because they might refer only one patient a year but a standardised referral form which prompted the inclusion of all relevant information would go a long way to solving the problem.
The study also suggested the criteria to be considered urgent may need to be relaxed slightly to allow more people to be fast-tracked although it was acknowledged that could create further capacity issues.
Raines said the reason for the delay in the less urgent cases came down to lack of resourcing when it came to colonoscopy services which was a nation-wide issue.
Changes had already been made in the years since the audit which had improved the system in the Bay of Plenty, he said.
Bowel Cancer New Zealand medical advisor Frank Frizelle agreed it was critical GPs provided the right information to allow people to be prioritised.
He said electronic referral systems which were already in use at some health boards solved the problem because it could not be submitted until all the necessary fields had been filled out.
While long waits were not ideal for anybody and understandably put stress on patients and their families, bowel cancer cells were slow growing so the delay did not usually affect a person's chance of survival, he said.
By the numbers
• Number of cases correctly identified by GPs as needing to be fast-tracked: 36
• Number of cases fast-tracked after referral review by specialist: 48
• Median wait time for fast-tracked diagnostic test: 21 days
• Number of people who should have been fast-tracked based on symptoms: 65
• Median wait time for patients not fast-tracked: 67 days