How do we communicate risk?
A. Herxheimer
UK Cochrane Centre, UK
We do it badly, for two quite different reasons: (1) the concept of
probability of harm is difficult to convey and explain clearly, particularly in
a brief consultation, and (2) we use the word ‘risk’ as a euphemism for ‘harm’,
though strictly it denotes only ‘probability’.
We must communicate that all interventions in health care can cause harms as
well as benefits, and that an intervention is only worth using when the benefits
clearly outweigh the harms. Both the benefits and the harms of an intervention
have four distinct dimensions1 – (a) the kind of benefit or harm; (b) their
intensity and duration; (c) the probability that they will occur; (d) if they
occur, their possible effects on the person’s life.
We want people if possible to understand the important benefits and harms
that we believe they should consider before choosing or accepting a treatment,
and to help them compare these with the benefits and harms of other treatments,
and of no treatment. Clinicians cannot communicate these complex matters without
thorough preparation and help; patients/clients need time to take them in and
opportunities to discuss them and ask questions. This means that both written
and spoken communication is needed, often on more than one occasion. A written
summary enables all the professionals in a community to use the same information
as the basis for their conversations with patients, who should then get
consistent messages from whichever doctors, nurses, pharmacists, etc, they
encounter. That can help them to understand the concepts, to minimise
misconceptions and misunderstandings, and so to save time and regrets.
A complication that can rarely be considered, let alone explained, is that
the benefits and harms of medicines vary greatly with dosage and duration of use,
as well as with the users’ individual characteristics; unfortunately rather
little is known about these important variations.
1. Herxheimer A. Benefit, risk and harm. Australian Prescriber 2001;
24:8.
