A new study has revealed 79 percent of New Zealand's GPs have completely closed books for new enrolments or are limiting them.
Some near-capacity GP clinics have said they are selecting which patients they enrol.
A survey of 220 general practice staff has found four out of five had stopped or limited their enrolments in the previous three years.
Royal New Zealand College of GPs president Samantha Murton told AM most doctors can only work sustainably with about 1000 patients.
"We all work extraordinarily long hours just to see enough patients that are on our books already," Dr Murton said.
"Many of us work for a certain population that we have, that we can... sustain the work for.
"In many areas, we are looking after, say, nearly 1800 patients because of the community we're in, other books being closed, people wanting to see us and we just can't say no - but, in many places, it becomes imperative to be able to say, 'Look... I've got enough work - I can't do any more.'"
Overall, the study, published in the New Zealand Medical Journal, found the problem had worsened since COVID-19.
This was stopping people from getting the healthcare they needed, the authors noted.
For Dr Murton, who wasn't involved in the study, New Zealand's healthcare access issues were at a critical stage.
"We need to be able to, somehow, increase the ability to enrol patients because we know that, if someone is enrolled with a GP, then their use of out-of-hours care is reduced... the conditions that they get are reduced and their mortality is dramatically reduced as well," she said. "It makes a huge impact having someone looking after your healthcare that knows you."
New Zealand's borders being closed for an extended period due to COVID-19 and fewer doctors entering the country "is probably one of the bigger factors in how this has gone ahead", Dr Murton noted.
Beyond that, "as the population grows, we haven't grown enough of our... GPs", she said.
"We need to increase that number as well."
Given the current state of the healthcare system, the findings were a cause for concern, said Dr Murton.
Her comments come ahead of the Government's expected health targets announcement on Friday afternoon.
