District health boards that do heart surgery cannot produce reliable comparisons of individual surgeons' patient complication and death rates.
And even if they could, they would be unlikely to make it public, they have indicated to the Herald in response to Official Information Act requests aimed at nudging our health system into line with Britain's.
In Britain the National Health Service offers public internet access to statistics about individual, named surgeons' complication rates, the death rate among their patients and other "outcome" data.
The NHS says: "Publication of the data means consultants' performance can be compared openly for a given specialty to help spread best practice and identify any issues that need investigating."
You can read, for instance, that cardiothoracic surgeon Edward Ernest John Smith's risk-adjusted patient mortality rate of 3.93 per cent was "okay" and "within the expected range".
The Herald asked for the data just before the OIA's 22-day summer holiday. The Auckland, Waikato, Capital and Coast, Canterbury and Southern DHBs in February gave themselves an extension before making a decision - against which the newspaper has appealed to the Ombudsman - in mid to late March. Days later the Medical Council publicly called for debate on the release of data on doctors.
The DHBs' spokesman, Canterbury's chief medical officer, Dr Nigel Millar, said in his letter, which reflects the other four: "The information you have requested represents, with current systems, a complex data extraction followed by an analysis that is not possible. In particular, the system from the NHS requires adjustments to the raw mortality figures based on other clinical information not currently readily available here."
The five boards supplied some DHB-level data on death rates from several kinds of heart surgery and neurosurgery, which can be found on the nzherald.co.nz Data Blog. It is raw data from which no reliable comparisons can be made.