People with chronic health conditions cost the accident compensation system 59 per cent more than healthy people without those conditions, researchers have found.
Although only a minority of people suffer from any of the conditions, their non-accident-related conditions account for 10.7 per cent of total accident compensation costs, or $276 million a year.
The findings, obtained by Accident Compensation Corporation clients Bruce Van Essen and Bronwyn Pullar under the Official Information Act, raise fears that ACC may try to avoid paying for costs that are arguably due to chronic health conditions.
"I can't understand why you would go to all that trouble to collect data and not use it," said Ms Pullar, who blew the whistle on ACC's poor privacy processes after she was sent almost 7000 ACC files about other people by accident in 2012.
A Wellington legal specialist on ACC cases, John Miller, said ACC was already increasingly refusing to accept compensation claims by pointing to "degeneration" that existed before an accident, often due to aging.