risk and the perception of risk

Introduction

emergency medicine is for the most part, an art form, a careful balancing of a multitude of concurrent risks, benefits, uncertainty and probabilities which the general population struggle to comprehend
as physicians we need to understand risk, how we perceive risk, how others may perceive risk, and our own experiential and aptitude biases
to help us navigate this, in addition to having a though clinical training and the benefit of experience, we also need to understand:
- diagnostic tests - sens, spec, PPV, NPV, etc
- Clinical research study designs
- Bayesian theorem of probability of disease, etc
- patient cultures, health literacy, their individual circumstances and what is important to them

voluntary risks are more acceptable than involuntary risks
- being involuntarily exposed to a carcinogen or toxin is more likely to cause far greater outrage than a much higher risk of driving a car
acceptance of risk is inversely proportional to prevalence
- the less people exposed to a risk, the more we will accept the risk
risk is generally measured against our risk of disease
- we are more likely to accept a risk if that risk is less than what we perceive our risk of dying from disease is
novelty and lack of understanding increases perceived risk
- the perceived risk of a new technology is likely to be higher than a familiar technology even though it may in fact be far safer
large numbers are difficult to get in perspective
- our perception of risk should be exponential with the number of lives in danger of being lost as the impact of each life lost on society is not just that of the one life but of their impacts on their family and society
- however, our difficulty with managing large numbers means that the first few deaths have a far greater impact on us per death than the deaths after several hundreds or thousands have died
- this is similar to how much we value money, when we have little, each dollar is of great value but if we own millions then each dollar is of little importance
- thus an incident in which a few people have been killed will have a disproportionate impact per person killed than a pandemic killing a million people