Bringing back the $5 co-payment for prescription medicines could see a jump in hospital admissions, a new study by New Zealand researchers says.

The Victoria University study of 71,502 people found those who did not pick up a prescription because they could not afford the $5 fee had a 34 per cent higher rate of being admitted to hospital.

Data was taken from New Zealand Health Surveys run between 2014 and 2019.

The study found nearly 6000 people in the sample reported not picking up a prescription in the previous year because they could not afford the $5 co-payment.

Among that group, 60 per cent were admitted to hospital during the study period, compared with 43 percent of those who were able to pay the fee.

Lead author Dr Mona Jeffreys acknowledges that there are a range of factors that led to people being admitted to hospital, but says the study had accounted for that.

"We didn't take anything else into account, just looking at whether or not they could afford a prescription," she says.

"My hope from this piece of research would be this would be taken as really good evidence to show that we should keep all prescriptions free for everybody."

Prescription charges also had a big impact on health equity, says Mona.

"For Māori, the prevalence or how common it is to not be able to afford a prescription is much, much higher. The impact of these prescription charges is much higher on Māori, on Pacific communities, on people living in deprived areas, on low income families."

The $5 prescription co-payment was removed on 1 July 2023. Prior to the 2023 election, the National Party announced it intended to reintroduce the co-payment, although the fee would not be charged to everyone.

In a statement, a spokesperson in the Minister of Health's office says re-introducing the co-payment in a targeted way will make sure that funds are freed up for other vital services, such as cancer care.

They say the Government has committed that the $5 prescription co-payment will remain free for people aged 65 and over and people on low incomes.

"These groups include some of the highest users of prescription medicine. By supporting Kiwis in most need, we will continue to help people stay well and out of hospital," says the spokesperson.

"The Ministry of Health is currently considering the policy approach to the $5 prescription co-payment in-line with the Government's commitment."

-RNZ.