Of Logos and Evidence Based Medicine

22 11 2012

One of my friends was on exchange and I noticed a logo on the said friend’s facebook profile.

Looks familiar?

It kind of resembled my own school’s medical society logo.

NUS MedSoc Logo

I recall, back in my first year, we had a short lecture on the history of medicine and the lecturer briefly spoke about the logo, with an amused look. Apparently there is a bit of confusion with regards to the symbol and strictly speaking, the Stockholm school uses it the way it should be, based on its roots.

The winged rod with two intertwined snakes is actually the Staff of Hermes (Mercury in Roman Mythology), known as the Caduceus. Some historians interpret it to symbolise “balanced exchange and reciprocity” which are values which drive commerce. Since Mercury is the “the messenger of the gods, guide of the dead and protector of merchants, shepherds, gamblers, liars, and thieves” this has come to symbolise all these aspects. It’s often erroneously used by Medical Societies, especially the commercial ones, and this can be traced to it’s adoption as the symbol of the US Medical Corps in 1902. Wikipedia covers this in more detail in a very readable fashion.

The actual symbol representing Medicine, based on Greek mythology, is the Rod of Asclepius, the god of healing and it comprises a single snake twined around a rod, as below.

The Actual Rod of Healing


After a lecture today though, I think the (misused) logo can potentially be re-interpreted in the light of Evidence Based Medicine (EBM).

Simply put, EBM is an approach where we use evidence to analyse treatments (and lab tests, physical exam techniques etc) to objectively figure out whether our treatments (or tests) actually work. This might seem like a mundane question to those outside of the field, because, if someone takes a pill and gets better, a treatment works right? The reality is a little bit more complicated than that. As a counter to that, I might ask, how do you know that the pill made someone better? They might have gotten better anyway in a few days. In addition to this, for long term illness, one sometimes has good days and bad ones.  With this in mind, researchers (who are often Medical Doctors, but this can involve people from various healthcare fields) design studies to tease out the various factors so at the end of it, one can be confident that the treatment is effective.

An extra element of complexity is added when we consider the fact that certain treatments can be potentially harmful. Drugs sometimes have side effects or may have dramatic effects which can cause harm under various circumstances. An example is the use of “blood thinners” to prevention ischemic strokes due to blood clots choking the blood supply to the brain. Blood clotting (or coagulation) is a chemical reaction where proteins in the blood clump together with cells to form a clot. The clotting of blood is important to prevent bleeding but in diseases of the blood vessels, there is an increased tendency for blood to form a clot and block blood vessels.  Blood thinners, or more accurately, anti-coagulants, impair this process. They don’t actually make the blood thinner. However,  in a legitimate bleed, you still do want the blood to solidify and cause the bleeding to stop. A consequence of blood thinners is that the bleeding may not stop in the event of an injury.

With this in mind, it is imperative that Doctors use research and figure out how to balance the risk of an uncontrolled bleed versus the risk of a stroke in diseases of the blood vessels. Part of this strategy is to use the right drugs (some are weaker and hence less likely to cause bleeding) and to understand the patient and disease better (those with severe disease may still need stronger drugs). These days, there is a cost element that doctors need to be aware of, and we also know that the more complex a treatment, the less likely patients are to accept it and it may be more difficult to follow it. What this means is that our role has become more complex and we need to “balance and negotiate” a multitude of factors when we treat people.

If you dig around a little, there is this uncanny symbolism to the myths and paraphernalia associated with Hermes. A publisher used the staff as an emblem with a biblical quote reminding one to “be ye therefore wise as serpents, and harmless as doves.” Seems a lot like an exhortation to be a critical thinker but to balance it with empathy for patients. Hermes is also the “messenger of the Gods” and seen as a guide. Doctors are often looked up as people who “know the science” and there is a huge expectation upon us to be able to communicate this to patients, to help work with them to tailor their treatment. He is seen as swift and cunning and a navigator, and people expect us to be on their side when it comes to navigating the vast an complicated realm of healthcare.

I smugly laughed back in my first year when the lecturer potentially interpreted the Medical Society’s logo as representing the “commercialisation” of medicine. However, knowing this background it seems amusingly appropriate.

And the bit about Hermes as the god of Gamblers? Here’s a quote from the Oxford Handbook of Clinical Medicine (aka the Medical student’s pocket bible).

“Rather, medicine is for gamblers. Gamblers who use subtle clues to change their outlook from pessimism to optimism and vice versa”





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