Hospitals spent hundreds of thousands of dollars on the nationwide nurses' strike in July.
Documents released to RNZ under the Official Information Act also reveal that there was just one incident report concerning harm to a patient because of the strike nationwide.
The papers do not say where it happened but say it was a drug error, attributed directly to the strike, but the patient did not suffer ongoing harm. A second drug error also occurred on the same day, 12 July, but was not directly attributed to the strike. That patient did not suffer ongoing harm.
Fifteen of the 20 district health boards responded to the request for information about the strike, which is understood to be the first involving all public hospital nurses - senior and others - in this country.
Responses covered payments to staff for strike-related duties; payments to locums or other contractors; the number of people involved in contingency planning for the strike and the hours spent on this; and the effect on elective or non-urgent surgery.
The DHBs that did not respond were Auckland, Canterbury, Southern, West Coast and Tairawhiti.
Of those that did respond, Wellington's Capital and Coast DHB spent the most of payments to staff, at $87,775. It said the payments were for "strike cover".
Bay of Plenty was next on $68,312, Wairarapa $24,515 dollars, Mid-Central in Palmerston North $15,320, and Nelson Marlborough $3227.
Nurses who went on strike were not paid, but those who did not strike were paid at the normal rates. Other staff were paid in accordance with their employment agreement.
The DHBs which responded estimated a total of about 18,000 hours were spent on planning for the strike.
The documents show intensive planning over six to eight weeks before the strike, and signs of nervousness by health boards about how it would go. They listed 33 patient or business-related risks posed by the strike.
Fifteen DHBs responded that just 49 elective or non-urgent operations were done nationwide on 12 July, compared to 800 the same day the previous year. However, the data shows 49 is similar to such operations done on other weekend days this year.