About 140 Northlanders will have their outpatient appointments moved and a further 25-30 will have their elective surgery rescheduled as a result of the five-day resident doctors' strike.
The strike, which runs from today until Friday, is the latest in a long-running dispute between the NZ Resident Doctors Association and DHBs.
Resident doctors are accusing the DHB of wanting full control over their rosters.
RDA spokesperson, David Munro, told Newstalk ZB he is hoping the strike will force the DHB to compromise.
"There has been a lot of mischief from the DHBs, they make it sound like someone sits in the RDA's head office and makes some sort of decision... but it's a world away from the truth.
"The local medical team work out what are going to be the best arrangements, come up with what suits them best and the RDA is simply there to make sure that those arrangements don't breach any protections in the Multiple Employer Collective agreement, and that nobody is inadvertently agreeing to do anything unsafe of that will be too fatiguing."
Northland District Health Board chief executive Dr Nick Chamberlain said patient safety is always its number one priority and it has undertaken extensive contingency planning to ensure patients are safe during this strike period.
"With this latest week-long strike, in the past six months Northland DHB will have had 20 days of strike action where outpatient and planned surgery has had to be cancelled or postponed. Realistically with our shortage of new operating theatres (two new 'theatres' will be built and opened in 2020) and limited private surgical capacity, this adds a month to our waiting times."
Chamberlain said the strike particularly impacts on Whangārei Hospital. He said the senior doctors and locums will be covering shifts during the strike period and not all resident doctors - also called Resident Medical Officers (RMOs), Doctors in Training or Junior Doctors - employed by the DHB are striking.
"We have 130 resident doctors working at Whangārei Hospital and more than half of them are not striking, and they have chosen to come to work which is extremely helpful and something we are grateful for."
Whangārei Hospital services will have reduced staffing levels and will look to transfer those who can be, to their home hospitals in rural Northland.
Chamberlain said the DHB did not want to discourage anyone who has significant concern for their health from seeking help but patients need to understand their services are under greater pressure than normal.
There may be long waits, and if a GP, White Cross After Hours service or a pharmacy can deal with the problem, people are asked to avoid Whangārei's emergency department.
People can also call Healthline on 0800 611 116 24 hours a day or in an emergency, 111.
"Northland DHB have had good rosters for over 10 years with our first year doctors working a maximum of 10 days on, four days off; we comply with all our contractual obligations, and each year we are recognised in surveys by resident doctors as one of the best DHBs in the country for looking after them, and one of the best places to work," Chamberlain said.
"We encourage our staff to take care of themselves, and we certainly don't expect them to work under fatigue. I know that this desire genuinely exists among DHBs throughout NZ."
Facilitation for the long-running dispute has been set down for May 9, 10, 13 and 14.