The act of being made aware and acknowledging that medicine is not an exact science is as important for trainee physicians as it is for worried patients. By Melanie Cheng.

Medical uncertainty

In Australia, data suggests that over testing of patients is a growing problem.
In Australia, data suggests that over testing of patients is a growing problem.
Credit: Andrei Rahalski / Alamy

“Test me for everything.”

This is my least favourite opening to a consultation – one of several minefields in the landscape of medicine. The easiest way to respond is to order a few blood tests and, when they come back normal, reassure the patient that everything is fine. But this would be dishonest. The patient who requests a test for everything is in fact seeking the impossible: certainty with regards to their physical health.

When I graduated from university and began working in a hospital, I was shocked. As a student, medicine had seemed neat and methodical. Difficult, sure, but only in the manner of a complex mathematical equation. There was always a solution and if, at times, that answer proved elusive, it came down to deficiencies in the mind of the person attempting to solve it.

In real life, however, the practice of medicine proved extraordinarily messy. The textbook cases I had studied late into the night during medical school didn’t seem to exist outside of the textbooks. Instead, I was met with constellations of non-specific symptoms. A dizziness in the stomach. A floating sensation. A sore throat triggered by drinking hot milk. Even now, after almost 20 years of practice, I regularly tell my patients that while modern medicine is great at excluding the serious, life-threatening stuff, it’s not so great at narrowing things down to a specific diagnosis. Put more simply: I’m sorry but I just don’t know what’s wrong with you.

Somewhere between 10 and 20 per cent of presentations to general practice involve unexplained medical symptoms. Uncertainty is something I’ve had to learn to sit with as a GP. And many times, I’ve had to invite my patients to sit there with me. This is not an easy thing to do, for either of us. I suspect our discomfort arises, in large part, from a lack of practice. I know I never received any training on the subject of uncertainty during my undergraduate medical degree – an experience consistent with recent articles published in The BMJ (British Medical Journal) and The New England Journal of Medicine, both of which point to a deep-rooted unwillingness to acknowledge uncertainty within the medical community.

Such attitudes have even infiltrated our popular culture. Television shows such as House perpetuate the myth that a diagnosis can always be found, if only enough young doctors put their heads together with a whiteboard and an eccentric consultant on hand. Just last month, a group of frustrated GPs in Britain penned an open letter to the patients of Ivy Grove Surgery in which they wrote: “Real medicine is nothing like on TV medical dramas where not only a complex diagnosis can be made but also that it is fixed before the closing credits”.

In 2021, we are intolerant of imperfection. This intolerance extends to everything from a haircut to healthcare. We are perplexed, at times angry, when health experts get it wrong. How can this be? we decry on social media. And while we may like to believe advancements in medical technology will ultimately reduce our uncertainty, such advancements often only add complexity to already difficult discussions around risk and probability. The consequence – and one we have observed during the coronavirus pandemic – is that the level of health literacy demanded from the general population by the medical community is extraordinarily high.

Long before the pandemic, I was working at a community health centre in the western suburbs of Melbourne. The patients were predominantly from working-class backgrounds and the majority were first- and second-generation Australians. Health literacy among this group was low. But as a general practice registrar I was still coming to terms with this reality and it is with some regret that I now recall many of my early consultations at that practice.

I distinctly remember, for instance, counselling a young mother about first trimester screening. The woman had left high school in year 10 and fallen pregnant with her first child not long afterwards. During this particular consultation, I had confirmed she was seven weeks pregnant with her second child. Keen to ensure that the young woman was aware of all her options, I launched into a discussion about first trimester screening. “If you decide to have the test,” I began, “the result will come back as either low or high risk. A low-risk result is reassuring but doesn’t completely exclude a chromosomal abnormality. A high-risk result doesn’t necessarily mean there is an issue with your baby…” As I spoke, I watched new frown lines form across her youthful face.

For all our complaints about a diminishing respect for scientific expertise, many patients still place enormous faith in modern medicine. I’ve lost count of the number of times female patients have assumed their recent Pap test screened them for not only cervical cancer but all gynaecological malignancies. It is likely the new and renamed cervical screening test will go some way to addressing this misunderstanding, but it is also the responsibility of health professionals to ensure patients are not the unwitting victims of such false assumptions.

Doctors know that the patient who requests a test for everything often has cancer at the back of their mind. A little bit of probing will frequently reveal that a close friend or relative has recently received a cancer diagnosis. On occasion, the friend or relative in question has even encouraged the patient to present to their GP for testing.

Unfortunately, what this well-meaning friend has failed to tell the patient is that modern medicine is not yet capable of testing for all types of cancer. Some, such as cervical cancer and bowel cancer, lend themselves to screening because non-invasive tests exist, with good sensitivity and specificity for picking up the disease. But other cancers – ovarian cancer being the one I get asked about most frequently – don’t have the benefit of such reliable screening tests. In a landmark research paper published in a recent edition of The Lancet, scientists confirmed that screening for ovarian cancer using a combination of ultrasound and tumour markers does not, sadly, save lives.

In Australia, data suggests that over testing of patients is an important and growing problem. In addition to the financial burden, there is the very real issue of iatrogenic harm – illness caused by medical examination or the treatment itself. Incidental findings that pop up on well-intentioned blood tests can unleash a cascade of further blood tests, X-rays and other invasive investigations, all of which serve to increase, rather than decrease, patient anxiety. I’ve seen this occur many times. More times, in fact, than I’ve seen a case of ovarian cancer.

It’s not easy to look a patient in the eye and tell them you can’t be sure they won’t get cancer. Nor is it easy to face expectant parents and tell them you can’t guarantee them a healthy child. As a medical student, I never envisaged I would one day be negotiating such fraught conversations with my patients. To some extent, I feel let down by my lecturers, who had me believe that medicine was a precise science, and if I studied hard enough, I, too, could have all the answers.

The medical profession hasn’t always been so rejecting of uncertainty. In the process of researching this article, I learnt that medical uncertainty was not only acknowledged but discussed extensively by prominent doctors as far back as the 19th century. It was Sir William Osler, the Canadian physician and founding professor of The Johns Hopkins Hospital, who said, “Medicine is a science of uncertainty and an art of probability.” I wish someone had gifted me that quote 20 years ago.

This article was first published in the print edition of The Saturday Paper on May 29, 2021 as "Looking for answers".

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Melanie Cheng is a doctor, writer and The Saturday Paper’s health columnist.

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