Risk

From Ganfyd

Risk is the product of how bad an outcome is likely to be (the hazard), and the likelihood of that bad outcome coming to pass.

Communication

The communication of risk^[1] between doctors and patients is difficult. Seen in retrospect imprecision is capable of causing trouble. Numeracy helps.^[2]

"Is it safe doctor?"

How to Communicate

See [^[3]] as most consultations are good practice for that media interview or court professional witness interrogation that most hope will never come.

Calculation

Various calculators, medical algorithms and lookup tables such as the New Zealand and Sheffield cardiovascular risk tables are provided or proposed to help doctors and sometimes directly patients estimate the risk for particular events or complications.

Attempts have also been made to quantify risks in individual patients for a variety of other problem activities, e.g. self-harming or suicidal behaviour.

Perception

The main issue in clinical medicine with risk is that it is overwhelmingly perceived on subjective grounds despite the entire science of clinical statistics having developed to objectively evaluate risk. As outlined above communication of risk is challenging because health professionals are likely to have a different subjective perception of risk to their non clinical peers (university graduates), yet alone patients from a totally different cultural background. Human beings, including doctors, develop bias as a result of their cultural background. Common bias in evaluating risk that is hard wired into the functional adult include:

• Negative or adverse outcomes for an individual are retrospectively given more weight than good outcomes
  • This perception distortion is likely to have a survival advantage for the individual
• Risk associated with commission is given more weight than risk associated with omission
  • Optimism is likely to have a survival advantage for the individual. Most associate global warming with the commissions of carbon based energy exploitation or felling the topical rain forest for agriculture rather than the omissions of instituting a sustainable energy economy when it first became apparent that nonrenewable carbon sources like coal, oil and gas were finite or developing adequate birth control mechanisms when populations exceeded long term carrying capacity.
• Risk perception is based on criteria that optimise reproductive fitness for the population rather than morbidity or mortality
  • An identical absolute risk of adverse outcome in a child and elderly adult have markedly different cultural and individual perceptions

Risk is the chance of an adverse event happening Harm is the unfortunate consequence of the adverse event.

• Relative risk is different to absolute risk (Generally, discussing absolute risk is better).
  • Most objective data relates to relative risk which is likely to be even further from a patients perception of absolute risk that they use in decisions as to whether to smoke or take another recreational drug say, yet alone medical advice.

Tools

Multiple tools are available to aid in communicating risk. Often they take the form of pictorial representations. Again a key point is that such representations can make assumptions with respect to individual perceptions and a tool that is better for most may be confusing for an individual who has a different world view to most.

External links

• Communicating Risk in a Soundbite - essential reading
• Center for Risk Perception and Communication, Carnegie Mellon University
• Riskworld - Links to many Risk Communication web sites with US bias
• Cancer Research UK on Understanding Risk Risk communication in malignancy
• Risk Communication - A Guide to Regulatory Practice-how in the UK you should spin risk if a public organisation
• A Primer on Health Risk Communication Principles and Practices or Risk Communication-how in the USA you should spin risk if a public organisation

References