In February, these five DHBs granted themselves extensions under the Official Information Act. Last month they all replied with a co-ordinated response, saying they could not supply the information.
But they did supply a variety of information at the DHB level, not surgeon level, on complication and death rates for cardiothoracic surgery and neurosurgery. For statistical purposes, the numbers are small and no attempt has been made to adjust them for the different risk factors of the different populations so no comparative conclusions can be drawn.
The DHBs' spokesman on the Herald's request is Dr Nigel Millar, Canterbury DHB's chief medical officer.
He told the Herald in an interview that the DHBs do not hold the information we sought, although they are building the necessary systems and expect to have some of it in a year or two. Whether they release it to the public is another matter.
The Herald has asked the Office of the Ombudsman to rule on the DHBs' responses.
The UK National Health Service offers consultant outcome data to the public by various surgeries.
Partly because of the Herald's request, the Medical Council of New Zealand - which is not subject to the Official Information Act - circulated a public and health-sector discussion document calling for debate on data on individual doctors, localised services and regional and national health systems.
Council chairman Andrew Connolly said the main question is what is the value of accurate performance and outcome data.
"It is important to examine the arguments for making more performance and outcome data publicly available, particularly where it relates to individual clinicians. It needs to serve more than just a 'right to know' purpose."
Dr Millar doubted whether there would be agreement in the health sector to release surgeon level complication data.
He said a key problem New Zealand would face is the inherent unreliability of the results because of relatively small numbers of cases.
Citing a London study, he said: "To have a 60 per cent chance of showing a real doubling in mortality per surgeon in cardiac surgery you have to do around 180 procedures a year. Sixty per cent of the time you would find that difference and 40 per cent of the time it would be invisible to you."
"You are going to struggle to find and issue unless it's so extreme it's extraordinary."
"I'm not arguing against having this sort of information. There are just a lot of caveats."
"The work is under way in cardiac interventions. There's a programme running now that's been set up and led by a combination of district health boards, the Health IT Board, the cardiac surgeons and cardiologists to collect very precise data around cardiac intervention surgery and medical interventions."
Will this be able to provide data on individual surgeons and cardiologists?
"Yes it will be able to provide that. I don't know whether people will agree to that, but that information will be available.The primary reason for us to do this in the first instance is to improve the quality and safety of what we offer, and deal with and correct issues as they arise. Publication of it is of some utility ... but it's not the prime aim, the prime aim is to make things better."