TESTING
TREATMENTS - BETTER RESEARCH
FOR BETTER HEALTHCARE
CHAPTER IV - Excerpt
DEALING WITH UNCERTAINTY ABOUT
THE EFFECTS OF TREATMENTS
In the 1970s,
one of the authors (IC), while holidaying in the USA, broke an ankle
and was treated by an orthopaedic surgeon. The surgeon put the leg in a
temporary splint, recommending that the next step, once the swelling
had subsided, would be a lower leg plaster cast for six weeks.
On returning home a couple of days later, IC went to the local fracture
clinic, where a British orthopaedic surgeon, without hesitation,
dismissed this advice. Putting the leg in plaster, the surgeon said,
would be wholly inappropriate. In the light of this obvious uncertainty
about which treatment was better, IC asked whether he could participate
in a controlled comparison to find out. The British surgeon answered
that controlled trials are for people who are uncertain whether or not
they are right – and that he was certain.
How can such a pronounced difference in professional opinion come
about, and what is a patient to make of this? Each surgeon was certain,
individually, about the correct course of action. Yet their widely
divergent views clearly revealed uncertainty within the profession as a
whole about
the best way to treat a common fracture. Was there good evidence about
which treatment was better? If so, was one or neither surgeon aware of
the evidence? Or was it that nobody knew which treatment was better?
Perhaps the two surgeons differed in the value they placed on
particular outcomes of treatments: the American surgeon may have been
more concerned about relief of pain – hence the recommendation of a
plaster cast – while his British counterpart may have been more worried
about the possibility of muscle wasting, which occurs when a limb is
immobilised in this way. If so, why did neither surgeon ask IC which
outcome mattered more to him, the patient?
There are several separate issues here. First, was there any reliable
evidence comparing the two very different approaches being recommended?
If so, did it show their relative effects on outcomes (reduced pain, or
reduced muscle wasting, for example) that might matter to IC or to
other patients, who might have different preferences to his? But what
if there was no evidence providing the information needed?
Some clinicians are clear about what to do when there is no reliable
evidence. For example, one doctor who specialises in caring for people
with stroke has put it this way: ‘I can reassure a patient that I am an
expert in stroke assessment and diagnosis, and that I can reliably
interpret the
brain scan, and order the correct tests. I also know from existing
research that my patient will fare better if cared for in a stroke
unit. However, there is one aspect of management that I and others are
uncertain about, and that is whether I should be prescribing
clot-busting drugs: these drugs may do more good than harm, but they
may actually do more harm than good. In these circumstances I feel it
is my duty to help reduce this uncertainty by explaining to my patient
that I am only prepared to prescribe this treatment within the context
of a carefully controlled comparison.
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