One in 10 New Zealanders don't feel comfortable about asking their doctor whether a treatment or test is necessary.
That's according to a survey, conducted by Consumer NZ and the Council of Medical Colleges, that tested 1069 New Zealanders over the age of 18 years.
This is an issue because patients need to understand why their doctor is considering a test so they themself can weigh up the benefits and risks, Consumer NZ chief executive Sue Chetwin said.
"It's every patient's right," Chetwin said.
The survey also revealed 21 per cent of participants felt their doctor had recommended a test or treatment that wasn't necessary.
Of those, 24 per cent said they went ahead and had it anyway.
Over a third of all participants agreed or strongly agreed some tests or treatments did not benefit the patient.
While most felt their doctor always (40 per cent) or often (30 per cent) involved them in decisions about their care, one in five thought this only happened sometimes.
Choosing Wisely medical director Dr Derek Sherwood said while modern medicine had given us more ways than ever to diagnose and treat illness, sometimes, the best option may be to do nothing.
He explained tests, treatments and procedures had side effects and some may even cause harm.
"For example, CT scans and x-rays expose you to radiation, overuse of antibiotics leads to them becoming less effective and a false positive test may lead to painful and stressful further investigation," Sherwood said.
The annual survey was carried out as part of Consumer NZ's Choosing Wisely campaign which encourages people to ask their health professional four questions when a test or treatment is suggested:
1. Do I really need this test, treatment or procedure?
2. What are the risks?
3. Are there simpler, safer options?
4. What happens if I don't do anything?
Choosing Wisely sponsors are the Council of Medical Colleges, Southern Cross Health Society, Pacific Radiology and PHARMAC.
Consumer NZ and the Health Quality and Safety Commission are Choosing Wisely partners, and there is wide health sector support for the campaign.