New Zealand's largest privately-owned healthcare group is having to intermittently close urgent care and general practice clinics due to staff shortages in Auckland.
Tāmaki Health runs the seven-days-a-week White Cross clinics, but the New Lynn, Glenfield and Mt Wellington clinics have been cutting back opening hours and days.
Health workers are under extra pressure as vaccination drives ramp up and winter illnesses spread.
Chief executive Dr Lloyd McCann said Tāmaki Health had tried to avoid the closures "at all costs".
"Wherever possible, we… haven't been turning people away, we've been diverting people to other clinics where we have been able to consolidate and to keep opening. A number of our larger hubs will see 300 to 350 patients in a day, so these are significant numbers of people where access is a challenge."
He said overall, Tāmaki Health was short of between 30 and 40 nurses and doctors - and a large part of the problem was the exodus overseas, as health workers sought higher pay.
"Jurisdictions like Australia have obviously just thrown millions of dollars at this problem, so the the exodus we have seen from a nursing and doctor workforce perspective has been severe. It's something, again, that I think has been exacerbated in the last few months, because this is not a New Zealand-specific issue. This is actually a global issue."
The closures in Auckland are temporary, and some days doors do still open at clinics with roster gaps - but for eight hours a day, instead of 12 or more.
Royal College of GPs medical director Dr Luke Bradford said disruptions like these were not the norm across the country - but flu and Covid-19 were on the rise, and this would hit rosters even harder.
"It's the last resort for any clinic to not be able to offer services."
He said despite the government's efforts to fast-track immigration pathways for doctors and nurses coming into New Zealand and expand training spots and incentives, there was not relief in the short-term.
"The cavalry has not yet arrived, and there's still much work to do around recruiting and retaining the workforce. The amount of time obviously it takes to train someone varies and can be up to eight or nine years for a vocationally registered GP, from the moment they are accepted at medical school. So that's not an instant fix.
"And so we do know that there are going to be pressures across the primary care system this winter."
With hundreds of White Cross appointments being rescheduled - or in some cases, cancelled- Te Whatu Ora said in a statement: "Where community services such as those provided by White Cross aren't available, we work with other community providers and our local hospitals to ensure New Zealanders can always access care when they need it."
The statement also said: "It is difficult to measure the potential impact on our hospitals and EDs, which continue to remain very busy, as is normal at this time of year."
ACC chief clinical officer and head of health partnerships Dr John Robson said, also in a statement: "We are aware of the significant workforce challenges within primary and acute care, which have made it difficult for some urgent-care clinics to maintain their contracted opening hours, and we continue to work with the health sector to find a sustainable long-term approach."
"We appreciate that workforce development is a significant issue for a number of health professional groups," Dr Robson said.