An "early intervention strategy" may be key to preventing the level of misdiagnoses that allegedly occurred at a hospital pathology lab in northern New Brunswick, a public inquiry heard on Tuesday.

Dr. Denis Kendel, registrar of the College of Physicians and Surgeons in Saskatchewan, testified before the public inquiry into the faulty cancer biopsies in the pathology lab at the Miramichi Regional Hospital.

Kendel said the Saskatchewan college has used an accreditation program for its medical labs since 1992 and conducts proficiency tests at least three times a year.

Kendel said the program doesn't look at the interpretations of the pathologists but it does look at diagnostic imaging and radiologists as part of its quality assurance program. Including pathologists in the review would improve safeguards even more, he said.

There's not a similar program in New Brunswick, he said, but implementing one in that province may provide an "early intervention strategy" to help identify any problems with testing before they become a problem.

The inquiry has entered its final phase — 18 days of hearings at the University of Moncton. There will be about 20 expert witnesses, including representatives of the Canadian Association of Pathologists, the New Brunswick Medical Society and medical experts from universities in the United States.

New Brunswick Health Minister Mike Murphy called the inquiry after an independent audit of 227 cases of breast and prostate cancer biopsies from 2004 to 2005 found 18 per cent had incomplete results and three per cent had been misdiagnosed.

More than 23,700 patient cases from the northeastern New Brunswick hospital from 1995 to 2007 are being reviewed by an Ottawa lab. The audit will also include about 100 cases carried out for Regional Health Authority 4 in Edmundston, N.B., in 2002.

The tests were conducted by now-suspended pathologist Dr. Rajgopal Menon.

In the initial two phases, the inquiry heard testimony from health officials, affected patients and Menon.

Witnesses in the final phase will give opinions on whether New Brunswick's pathology laboratories need an overhaul.

The inquiry will not assign any legal responsibility for the misdiagnoses.

Justice Paul Creaghan is expected to make recommendations to the government by Jan. 1 on how to prevent any further misdiagnoses.