This story is a good
example that goes along with a previous post about treating (and correcting) surrogate
factors (like X-rays and blood tests) instead of treating patient health (see:
The map is not the territory). In this case, hypothyroidism (low thyroid
hormone levels) in older people comes under the spotlight. If patient don’t
have any symptoms, it is still often treated in order to correct the ‘disease’
state. But as researchers found in this randomised trial, replacing their thyroid hormone
(compared to placebo) definitely improved the thyroid hormone levels in the
blood, but it did nothing to any other outcome measured. It didn’t help the people
being treated.
This is a classic
example of overdiagnosis – discovering an abnormality in some people (a low thyroid
hormone level is common in older people) and labeling it a disease. Doing so
then leads to overtreatment aimed at addressing the ‘abnormality’ rather than
aimed at improving the health of the patient. This last part is the trick of
overtreatment – correcting things in our body is surely good for us, right? No, not always. It needs to be shown that it is
– not assumed. And any benefit shown needs to outweigh any unintended
consequences and direct harms from the treatment.
The other problem I
have with the problem of overdiagnosis and overtreatment is that the research
that shows them wrong comes so many years after the practice has become
entrenched (like in this case), making it much harder to undo common practice
than if the research was done before
the treatment was introduced.