Accepting risk
It
is often said that health and safety at work legislation was introduced so that
employees were fit to go hang-gliding at the weekend. Bandolier shudders at the
thought of leaping off a cliff supported by a thin piece of fabric: it is a
risk too far. But what constitutes a risk too far for patients? A study from
Boston suggests that many patients are highly risk averse.
Study
Participants
were 346 adults presenting at an emergency medicine department in Boston. They
were presented with a questionnaire about a hypothetical diagnostic situation
as part of a clinical trial, with a series of risk statements. They were asked
whether they would agree to have the test or refuse to have the test depending
on the statement, or they could indicate that they did not understand the
statement.
The
test was radioactive Technetium as part of a diagnosis of chest pain to help
identify its origin, which could not be determined using standard tests
available in the emergency department. The trial involved using the test,
already an established and approved procedure, in the emergency department,
where its use was considered experimental. Participants were told that the
procedure was safe, approved, and used by doctors every day. The six statements
said that the risk to them of having the test were:
- The same as 20 chest x-rays.
- The same as 10% of the federal limit for occupational radiation workers.
- The same as five times the natural radiation background received in one year by living in Boston.
- The same as breathing radon in a house for 2.5 years while living in Boston.
- The same as the risk of dying from lung cancer by smoking 30 packs of cigarettes.
- The same as the risk of dying in a car accident from driving 1,500 miles.
Results
The
346 participants were aged 15 to 82 years, with a median of 34 years, with a
mixture of ethnicity and education.
Whatever
risk presentation was used, more refused the hypothetical test than accepted
it, with differences between presentations (Figure 1). Some (7%) accepted the
test with all six presentations, and 16% refused the test with all
presentations. Participants with higher educational levels were somewhat more
likely to view all the risk presentations as equivalent.
Figure 1: Proportion of participants accepting or rejecting participation in a hypothetical trial based on six different statements of equivalent risk
Comment
There
are two ways of looking at this. One is as an interesting investigation in
different ways of presenting risk. The other is that whatever the presentation,
most were put off by any presentation of risk from participating in a sensible
study for sensible reasons with probable important implications for their own
well being.
To
recall, the scenario was that they had come to hospital with chest pain that
could not be diagnosed by standard means, and that doctors were asking them to
participate in a trial using a safe and approved test involving a small amount
of radioactivity that might help make a diagnosis. The only question was where
the test might be carried out.
Participants
lived in Boston, and several of the risks related to living in Boston, or were
related to activities many of them accepted already, like smoking or driving.
Yet most of them were averse to accepting even a tiny increase in risk in this
situation.
The
message appears to be that we don't want any tiny extra risk to interfere
with our hang-gliding. The implication just could be that many patients would
refuse treatments if told what their risks were. We all need to think about this.
Reference:
- JA Feldman et al. Evaluating acceptance and understanding risk in the emergency department: are all risk statements created equally? Academic Emergency Medicine 2002 9: 309-316.