District health boards have suggested Otago University researchers come back to them for more specific information, after a study about their spending found it was poorly monitored.
The Otago Business School study found the country's health boards were spending between $10 million and $60m a year on outside advice, and just six of the 20 boards had formal policies on seeking and using consultants.
However, DHB spokesperson Ron Dunham said the questions the researchers asked could have confused those providing the answers.
He said health boards did observe robust policies when engaging consultants.
"There are very explicit requirements from the government around procurement with recent changes in the act so there are policies that are there and commissioning major projects has some very strict criteria.