The certainty of ambiguity

In wake of the Ruth Morrissey case judgment in the High Court, Dr Michael Conroy argues the Government needs to accept that uncertainty is part of medical life

A book called The Curious Incident of the Dog in the Night-Time was a little treasure of my teenage years. It’s a murder-mystery told from the perspective of a 15 year-old boy with Asperger syndrome, Christopher Boone, who delivers detached, dry descriptions of tragedy (and love) that would leave most of us in pieces. His only love is mathematics and his teacher explains that this must be because maths involves strict rules, certainty and structure, which are naturally appealing to a boy with Asperger’s. Christopher disagrees, though. He tells of the ‘Monty Hall problem’, a controversial puzzle from the world of probability. Experts worldwide cannot agree on the correct answer (Google it to see whose side you’re on) and all of those ‘strict rules’ and absolutes simply disappear into the ether. His lesson is that certainty is an evasive creature in this life, even when we feel we most expect and deserve it.

My relationship with maths was probably one of the more successful ones of my teenage years, and this was the only part of Christopher’s story that was neither welcome nor fully understood at that time. And in a life governed by rigid timetables, marking schemes and dress codes, maybe it wasn’t surprising that nuance and ambiguity didn’t sit well with me. It’s also clear why I, and other people of this bent, fit so neatly into the world of medicine in university. Clinical medicine is introduced as a series of straightforward equations that impose a comforting structure and order onto the unruly world of human ailments: Fever plus murmur equals endocarditis. ‘Homeless’ plus cough obviously equals TB. And if someone has aortic regurgitation then, as sure as night follows day, they will offer you a Corrigan’s pulse, De Musset’s sign and Austin Flint murmur (one day).

Except it’s not really like this at all, is it? From the moment we begin as interns, the black and white of our medical universe seep into each other and drench our world in shades of grey. Patient symptoms are vague (‘muzziness’ always raises my blood pressure) and clinical signs are iffy or non-existent. Bloods are halfway normal and halfway not, and most of your charges have an elevated LDH that you have no idea what to do with. The radiologist’s report just isn’t sure about that ‘misty mesentery sign’ and has found a renal cyst that may be something or may be not (again!). And the pathologist, that rock of steadiness in this churn of ‘maybe’, has told you that ‘clinical correlation is required’. You’d almost feel like giving up.

But we don’t, because we realise rapidly that this is the real world, imperfect and messy, and your job is to navigate those choppy waters. Examinations and tests can give you varying levels of confidence but much of our job is still a question of judgement. Where I work, in oncology, I may have good evidence that a chemotherapy adds three months to the average patient’s life. But this is a long way from ‘certain’ and a galaxy away from knowing whether this treatment is the right choice for my patients, which is why there is still a doctor in the room.

Which brings me to recent events. Ruth Morrissey was, on 3 May, awarded €2.1 million by Justice Kevin Cross for negligence in the reading of her cervical screening slides. His judgment holds that ‘absolute confidence’ is the screener’s practical duty in relation to examination of cervical screening slides.

Furious reactions have been directed towards the judge in specific and the legal system in general. While I, too, am deeply unsettled by this ruling, I believe we need to better focus our anger. Due to a vacuum of Irish precedent in this area, Justice Cross based his judgment on a long-established precedent in British medical law, and the ‘absolute confidence’ threshold was actually endorsed by the defendants in this case, Quest Diagnostics.

The deficit here is rather one of our legislature, the Oireachtas, which needs to legislate to account for the realities of screening, while still acknowledging the wrong done to the women affected by this issue. A precedent stating that anything less than ‘absolute certainty’ in a screener’s mind should lead to an abnormal reading, is one that fundamentally misunderstands medicine in general and screening in particular. Our profession is steeped in uncertainty from the moment we answer that first bleep, and medicine inevitably involves judgement calls about what level of uncertainty we can acceptably expose our patients to. So it should: The alternative — legalistic decision-making at every turn, dangerous over-investigation and the overwhelming and stagnation of our health service as a result — is a dramatically worse situation than the status quo.

Uncertainty is part of being human and, as Christopher Boone discovered, we cannot simply purge it from our existence. Doctors have long learned to accept that, and maybe even to embrace it. It is imperative, for the sake of our health system, that our Government catches up fast.