Worst Case Thinking by Sue Ieraci, MD

Sue Ieraci, MDEmergency Medicine is about risk management. What we enjoy, and do well, is use clinical skills and reasoning to solve diagnostic and therapeutic puzzles. Sometimes there is relative certainty (for example, a straightforward injury), but generally we are dealing with probabilities. We “rule out” and send home with various degrees of confidence but rarely with complete certainty. That’s how our system works, and it almost always serves patients well.

This approach generally reflects what we were taught in medical school. We were encouraged to list differential diagnoses with the most likely ones first. We were taught that “common things occur commonly”, and advised to “look for horses, not zebras.” Aristotle and William of Occam understood this principle as “entities must not be multiplied beyond what is necessary” – AKA “the most simple explanation is the most likely to be true.”

Imagine what would happen if we did not behave this way. Anyone with almost any symptom would have to be admitted to hospital for the rest of their lives, in case the symptoms could possibly reflect a life-threatening cause. No surgery would ever be carried out because of the risk of complications. Internists would rule the world…

This is where we are headed if medicine follows the societal trend to “Worse Case Thinking”. The US security technologist Bruce Schneier says that worst case thinking (WCT) “involves imagining the worst possible outcome and then acting as if it were a certainty. It substitutes imagination for thinking, speculation for risk analysis and fear for reason.” (http://www.schneier.com//). He goes on to explain that WCT “means generally bad decision making” and leads to the result that “our society no longer has the ability to calculate probabilities.” (ibid).

Here’s where we come in. We need to explain to anyone who will listen that WCT does not produce good medicine. It devalues our cognitive skills, judgement and decision-making, leading to an overly cumbersome and extremely expensive system that is paralysed by fear. It does not improve clinical outcomes. Finally, it makes no-one feel better.

Comments

[Mike Sherriff]

That is one of the most frustrating things about Prehospital Medicine. By policy and by protocol we are directed to rely on the "ability [of our patients] to calculate probabilities." Even in the cases where there is a ridiculous lack of necessity for physician evaluation (let alone treatment), paramedics (most places) are expected to offer transport to the hospital. It is up to the patient or parent to recognize the paucity of risk. I'm not talking about risk stratification of chest pain, syncope or dyspnea; I'm talking about the bumps, bruises and nose bleeds of daily life.
And so we fill the ED's with low risk patients...and no doubt expose the patient to higher risks than they would have had if they had stayed home.
When a patient asks me, "Do I need to go to the hospital?" I would like my "cognitive skills, judgement and decision-making" to be trusted to the point where I am allowed to answer honestly.

Mike Sherriff EMT-P

[Sue Ieraci]

Mike - I really appreciate your situation. I encounter this increasing risk-aversion among pre-hospital personnel all the time - motivated by the risk-aversion of the management structure, and fear of being blamed for adverse events. For example, a team stopped at our ED the other day with a palliative care patient (disseminated cancer as well as respiratory disease) who was on their way to a booked bed in the palliative care unit. They were worried that somehow this patient was too sick for palliative care, and were advised by the Palliative care staff to take him to an ED. I also see many people brought form minor motor vehicle crashes with essentially no injury, transported in hard collars (if they didn't have neck pain before that, the collar will make sure they do!). Do we really think people who get bumped and have little or no neck pain will have broken necks?

Risk aversion is everywhere - it is destroying our professionalism.
Sue