A study by Bond University academics, published in one of the world’s most influential medical journals, JAMA Internal Medicine, found most people overestimate the benefits of medical tests and treatments and underestimate their harms.
The research involved a review of studies that examined people’s expectations of the benefit or harm of any medical intervention, including treatments, tests and screening tests.
The review included 35 studies involving a total of 27,323 participants and it was undertaken by Associate Professor Tammy Hoffmann and Professor Chris Del Mar from the Centre for Research in Evidence-Based Practice, Faculty of Health Sciences and Medicine.
Across the review, a range of interventions were studied, including screening for various cancers, orthopaedic surgery, medications for cardiovascular disease and radiological procedures.
Studies from the review found many examples including: overestimating the benefits of medicines to prevent heart disease; overestimating the quality of life after a successful kidney transplant; overestimating the benefits of hormone replacement therapy for reducing the risk of hip fracture; overestimating the benefits of screening for breast cancer and prostate cancer.
“Every intervention has both benefits and harms, but most of the time the focus is largely on the benefits,” said Associate Professor Hoffmann.
“This is the case in conversations between patients and health professionals, news stories, advertisements for treatments and tests, and even research studies about the interventions."
Associate Professor Hoffmann said there were many likely reasons for the optimistic expectations people have.
“Both patients and health professionals want treatments to be effective, and the drive to do something, rather than nothing, is strong," she said.
The paper describes a vicious circle: people with overly optimistic expectations request interventions from their clinician - clinicians are more likely to provide the intervention if it was requested, even if they feel uncomfortable with the request and believe it to be unnecessary, and because patients then receive it, their belief that the intervention is effective is reinforced.
Professor Del Mar said people largely assumed 'more health care means better care', but this was often not true.
“Overly optimistic expectations by patients and the public are undoubtedly contributing to the growing problem of over diagnosis and overtreatment,” he said.
The academics concluded that patients have a right to be fully informed about benefits and harms before making any decisions about tests, treatments or screening tests and that a routine part of the conversation with doctors should involve discussing these issues, and providing accurate, balanced and understandable information.
“One example of a reliable source of information is the Cochrane Collaboration - an independent, non-profit, non-governmental organisation consisting of a group of more than 31,000 volunteers in more than 120 countries,which has summarised evidence involving thousands of medical interventions,” said Professor Del Mar.
“The Cochrane Collaboration was formed to conduct systematic reviews of randomised controlled trials of health-care interventions, to facilitate the choices that health professionals, patients, policy makers and others face in health interventions according to the principles of evidence-based medicine.”