A University of Otago study shows Maori and Pacific Island people are going without medication because of the high cost of prescriptions.
The research group asked 18,000 people if they sometimes failed to get a prescription filled due to the price.
Fifteen percent of Maori and Pacific Islanders said yes, compared with only 5% of Europeans.
The senior researcher, Dr Santosh Jatrana, says this means many poorer people with chronic health problems are not getting the treatment they need and are putting their health at risk.
She says that could in turn have unfavourable consequences for the health system by increasing the number of emergency call outs.
Dr Jatrana says it's important that the cost barrier for prescriptions is broken down for those New Zealanders.