How many times have you seen the results of a new way of
doing things, where the results after the introduction were shown to be better
than they were before? These ‘before-and-after’ studies almost always show an
improvement, but does that mean that the improvement was caused by the intervention?
Given the example I will show you below, you should conclude that our highly
evolved tendency to read cause-and-effect into any association often runs
counter to reality.
Sunday, 7 April 2013
Friday, 5 April 2013
Book review: The wisdom of the body
Title: The wisdom of the body (1932, 1939)
Author: Walter B Cannon
Publisher: W.W. Norton & Company, New York
This book is old, but its subject and its message still hold.
The book is about homeostasis: how the body adapts to keep things in equilibrium,
despite forces that attempt to change the balance. This provides an important
lesson to those who attempt to influence the balance of anything in the human
body: the body will adapt, making the intervention less effective. A lesson that
many do not learn.
Wednesday, 27 March 2013
Book review: Meaning, Medicine and the Placebo Effect
Title: Meaning, Medicine and the Placebo Effect (2002)
Author: Daniel Moerman
Publisher: Cambridge University Press
In this book, an anthropologist offers an outsider’s view of
medicine. The book is not restricted to an examination of the placebo effect (in fact, the author suggests abandoning the term, instead using “meaning response”); it asks readers to see all of medicine (and indeed biology) in its social and
cultural context. The author shows that much of what we “know” isn’t
necessarily true (or more confusingly, that it might be true in certain contexts).
In that vein, he criticises doctors for dressing in science (empirical
evidence), but practicing experiential evidence, and therefore not being able
to see that what they “know” (based on tradition and their own experience)
might not be true (despite being able to construct biological mechanisms to explain the perceived effect).
Tuesday, 19 March 2013
Lessons from history #6: The Vioxx saga
The Vioxx saga contains everything: conflicts of interest, big
pharma influence, dodgy government regulators, data fabrication, and a body
count. But there is more to the story: it is an example of a common
logical fallacy whereby, when faced with a study that shows treatment A to be
better than treatment B, we assume that treatment A is providing a benefit, and
not that treatment B is harmful. Both assumptions may be equally valid, but we
tend to choose the former. Had we not done so in this case, Vioxx might not have
harmed so many people.
Sunday, 10 March 2013
Book review: Rethinking Aging: Growing Old and Living Well in an Overtreated Society
Title: Rethinking Aging: Growing Old and Living Well in an Overtreated Society (2011)
Author: Nortin M Hadler
Publisher: University of North Carolina Press, Chapel Hill
In his latest offering, Dr Hadler rehashes and updates many
of his familiar arguments (breast and prostate screening, cardiac stents,
osteoporosis, antidepressants, back surgery), this time applying them to the elderly. He adds
material specifically about growing frail and dying, and as usual, he provides
considerate, accurate, useful and often counter-intuitive information for the
would-be health care consumer.
Sunday, 24 February 2013
Keeping childbirth normal
The variation in cesarean section operation (C-section) rates during
childbirth is well documented; between hospitals, states and countries. The
rates also vary over time, but here the pattern is at least consistent: the
rate is increasing. So what? Sure there are complications, but isn’t that worth
it if we are saving lives? As usual, it turns out that we have been
overestimating the benefits and underestimating the harms of C-sections, which
may explain the overuse of this treatment.
Wednesday, 13 February 2013
The antioxidant myth
A recent
Scientific American article challenges the myth of antioxidants being
associated with ageing. This is not the first time SciAm has covered this topic
(here,
here
and here).
The article challenges current perceived wisdom, not only regarding the
effectiveness of anti-oxidants but of the underlying theory that oxidative
damage causes ageing. The current evidence tells
us that antioxidant supplementation is not only ineffective, it is harmful. The
sorry story of antioxidants should really be one of my “Lessons
from History” blogs, except that it has not yet been relegated to history. But
the story still provides lessons.
Sunday, 10 February 2013
Ethical double standards
Ethics committees (IRBs in the US) are now
firmly entrenched in the research environment such that clinical research can only be performed with
their approval. Clinical practice,
however, is not subject to such approval, yet in many cases the risk of harm
(individually and to society) from clinical practice is greater. Are
researchers being held to a higher standard than clinicians? Has our
concentration on ethical standards for clinical research led to an ethical blind
spot for clinical practice?
Sunday, 27 January 2013
Don’t just do something, stand there
This reversal of a commonly used phrase is a plea. A plea against
the bias that leans doctors towards diagnosing and treating, even when the
scientific evidence may not support it. Sure, it is expected that a doctor will
diagnose and treat you, but sometimes there is no diagnosis or effective
treatment, and pursuing either may be harmful. When in doubt, your doctor will
continue to run tests until something comes up, and will continue to treat you
for as long as you return with symptoms. Sometimes, not pursuing a diagnosis and not
treating a patient are reasonable options. Sometimes they are the best option.
Friday, 18 January 2013
Book review: Limits to Medicine
Title: Limits to Medicine. Medical Nemesis: The Expropriation of Health (1975)
Author: Ivan Illich
Publisher: Marion Boyars
Ivan Illich was a philosopher and historian who published
several books in the 1970s targeting areas like medicine, transport, education
and energy use. His thesis was that modern, western, industrialisation and in
particular the institutionalization of specialised knowledge by the professions
has far-reaching negative consequences. His 1975 book Limits to Medicine. Medical Nemesis: The Expropriation of Health made his case against modern, institutionalised medicine. He felt that more
expensive and specialised medicine was more likely to be harmful and less effective, and that
important aspects of the life experience such as birth, mating, suffering,
aging and dying were being medicalized. His points were interesting and
controversial in their time, and the following 40-odd years of growth in specialised
industrial medicine has made many of them prescient.
Sunday, 6 January 2013
Lessons from history #5: Bone marrow transplant for breast cancer
In the 1990s, giving patients with breast cancer massive
doses of chemotherapy or radiotherapy followed by a bone marrow “rescue” was
thought to improve survival and even cure the disease. It was complex, expensive and risky, which only raised the perceived effectiveness. The
treatment spread, and insurance companies had to fall in line to cover the
treatment due to legal, government and public pressure. The randomised trials
that were eventually done showed that it was no more effective than standard treatment.
Here is the story and the lessons that can be learned.
Saturday, 5 January 2013
Evidence based medicine vs the Golden Rule
I am a big fan of evidence based medicine (EBM). Not the
cookbook type (“do it this way or else”), but the idea that medicine is a
science and therefore should be approached scientifically. We should use the
principles of logic and rational thinking to reduce the errors that result from
our often irrational, subjective “human” way of making decisions. Sometimes,
however, we try to use EBM to justify something that doesn’t need scientific
support – something that should be the default, and only changed if there is
evidence against it. Something like the Golden Rule.
Tuesday, 1 January 2013
What's the deal with those bad hip replacements?
Most people are aware
that a year or two ago there were some new hip replacements that were recalled.
The story behind it has all the ingredients to suit this blog: overestimation
of benefit, underestimation of harm, regulation failure, and conflict of
interest up the wazoo. The ‘deal’ as it were, was a bad one for patients, a bad
one for the company (in the end), but a great one for the surgeons, as it
became the gift that keeps giving.
Wednesday, 26 December 2012
Book review: Overdiagnosed
Title: Overdiagnosed. Making people sick in the pursuit of health (2011)
Author: H. Gilbert Welch (with Lisa Schwartz and Steven Woloshin)
Publisher: Beacon Press, Boston
Overdiagnosed is
an attempt to change the conventional wisdom - the prevailing paradigm - that
early diagnosis is always a good thing and therefore that the best test is the
one that finds the most disease. He shows us the downside of our attempt to
make sure that nobody misses out on any potential benefit by failing to be diagnosed. He shows us that the dogma of early diagnosis is maintained by
overestimated benefits and a general disregard of the harms.
Saturday, 22 December 2012
How you die vs If you die
Which is more important: how you die, or if you die?
Research in medicine often uses mortality (death) as an important outcome. Death
(from any cause, so called ‘all-cause’ mortality) is easy to measure, it is not subject to misclassification, and it is the most important outcome for many
conditions and treatments. Many researchers, however, favour ‘disease-specific’ mortality (only counting the deaths from the disease being studied) rather
than all-cause mortality. The argument is that this measurement is more
sensitive to changes in treatments that specifically target that condition (as
there is less ‘noise’ from deaths from other causes). For example, it makes
sense to measure deaths from heart disease if you are testing the effect of a
treatment for heart disease. However, the use of disease-specific mortality can
be misleading, it is arguably less important, and it results in an overestimation of the
benefits and underestimation of the harms from many interventions.
Sunday, 16 December 2012
Book review: Bad Pharma
Title: Bad Pharma. How drug companies mislead doctors and harm patients (2012)
Author: Ben Goldacre
Publisher: Fourth Estate, London
Author: Ben Goldacre
Publisher: Fourth Estate, London
Ben Goldacre, a UK based doctor, has become a popular
medical and science writer. His previous book Bad Science was a big hit, he has popular web and Twitter
profiles, and he is a regular public speaker and newspaper contributor. His new
book, Bad Pharma, specifically
targets the problems with medicines. It does not restrict itself to the
pharmaceutical industry (although drug companies are the main target), the book also details problems with government regulators,
patient advocate organisations, doctors, medical colleges, governments, journals,
universities, academics and even ethics committees. Fortunately, the book also
offers solutions.
Saturday, 8 December 2012
Limits to medicalization?
The character Syndrome from The Incredibles pictured a world where everybody had super powers: “because when everyone is super, no one will
be”. If more than 50% of the population have depression, then what is ‘normal’?
What if it was 75% of the population? Are we witnessing a gradual approach to a
situation where we will reach the Last Well
Person? Is a well person simply a patient
who has not been completely worked up?
Saturday, 17 November 2012
Stop the medication train, the elderly want to get off
Overmedication (“polypharmacy”) in the elderly is a problem.
The debate about the appropriateness of individual medications is one thing, but
when you are taking 5 or more different medications multiple times per day,
the physical act of simply taking the
medication is a problem, let alone the adverse effects and interactions of all these
medications. So what happens when you stop taking them? You feel better, that’s
what happens.
Sunday, 11 November 2012
Lessons from history #4: RSI
Repetitive Strain (or ‘Stress’) Injury (RSI) is a syndrome of
arm / hand pain associated with certain activities. It is not a disease. It is
not an injury, there is no physical evidence of stress or strain, and it bears
little correlation with repetitive use. It is a social construct, influenced
more by psychosocial factors than mechanical factors, and has no clear
biological basis. Its history shows us how ‘unstable’ such labels are. Yet
despite being easy to refute, labels like these persist. They persist because
they serve a purpose and appear to fill a gap in our knowledge, and they are
more socially acceptable and easy to understand than the truth. They are
examples of medicalization.
Saturday, 3 November 2012
Opioids: the real opium of the masses
Opioids are strong pain killing drugs that mimic the body’s
own chemicals. Examples of prescription opioids include heroin (which
metabolises to morphine and was banned after 1925), morphine, oxycodone and
hydrocodone. As pain killers for acute pain, opioids work. However, over longer
periods they become less effective, have more adverse effects, and can lead to tolerance,
dependence, addiction, increased pain, and death. Here are some facts about long-term opioid use.
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