Doctors are failing to really listen to patients' views on how they want to be treated, suggests a study in the British Medical Journal.
The Dartmouth College research says working out a patient's preferences is as important as an accurate medical diagnosis.
Involving patients in discussions about treatment could cut the cost of healthcare around the world, they say.
Doctors should follow a three-step approach to engaging patients.
The BMJ analysis, written by three healthcare experts from the Dartmouth Center for Health Care Delivery Science in New Hampshire, US, is based on a report written for the UK's King's Fund, a policy thinktank.
In it they argue that "preference misdiagnosis" - misinterpreting or ignoring the patient's wishes - is a significant problem which is damaging to both doctors and patients.
The researchers say it can lead to, what they call, "silent" misdiagnoses - when doctors choose the wrong treatments because they fail to assess their patients' preferences correctly.
These misdiagnoses are "silent" because they go largely unreported.
While doctors are taught to concentrate on diagnosing the medical problem, the authors point to evidence which suggests doctors are not as good at setting out all the treatment options and finding out how the patient feels about them.
In one study they looked at, doctors believed that 71% of patients with breast cancer rate keeping their breast as a top priority, but the figure reported by patients was just 7%.
In another study of dementia, patients placed substantially less importance than doctors believed on the continuation of life with severely declining brain function.
Evidence also shows that patients often choose different treatments after they become better informed about the risks and benefits, say the authors.
One study found that 40% fewer patients preferred surgery for benign prostate disease once they were informed about the risks of sexual dysfunction.
But ensuring patients' preferences are not misdiagnosed is not as simple as asking the patient what he or she wants, explain the authors.
They say it requires doctors to complete three steps when talking to a patient.
They should adopt a mindset of scientific detachment; use data to work out what the patient's preference is likely to be and involve the patient in shared decision-making regarding their treatment.
Engaging the patient in discussion about treatment possibilities will help them become more informed about the options and make it less likely that their preferences will be misinterpreted or misdiagnosed.
Al Mulley, lead researcher and professor of medicine at the Geisel School of Medicine at Dartmouth, New Hampshire, said it had been estimated that the NHS could save up to £30 billion every year if people actively took ownership of their health.
He also said it was a universal phenomenon.
He added: "Most medical treatments involve choices and trade-offs. For example, screening programmes can bring real benefits but also serious harm, such as over-diagnosis.
"More than 100 years ago student doctors were told to 'listen to the patient, he is telling you the diagnosis'.
"Today, the rise in treatment options makes this even more critical, not only to reach a correct medical diagnosis but also to understand fully patients' preferences - and reduce the huge waste in time and money that comes from the delivery of services that patients often neither want nor need."
Anna Dixon, director of policy at the King's Fund, said the research supported the idea that patients should be helped to make decisions about their care.
"Not only does it find that this results in more appropriate treatment than currently achieved but, rather counter-intuitively, it results in dramatically lower intervention rates."
Dr Vivienne Nathanson, head of science and ethics at the British Medical Association said good medicine was about doctors using their knowledge and expertise to help patients make informed choices.
"Good decisions about treatment reflect both a patient's preferences, and the relevant medical evidence. Doctors try to help patients express their preferences and are aware that these sometimes differ from those of the 'average' patient.
"Exploring how the patient's preferences and values relate to the decision to be made requires a relationship of trust between patient and doctor."
--Courtesy of BBC News