When your doctor or Naturopath prescribes you a treatment, do you ever wonder how they can have some certainty that it works? In my experience, when I ask physicians from both professions how they know, the answer is often; “because I’ve seen it work”. For me, this is an incredibly disappointing response. Personal observation is one of the lowest forms of evidence in medicine. This is because our brains are exceptionally good at tricking us into seeing patterns and effects that aren’t there. When I have expressed this concern, what I usually get in return is a detailed explanation of the particular situation in which the physician ‘saw’ it work. Although these stories are often very convincing, I remind myself that I’ve been to many equally convincing magic shows, and have yet to convert to a career in sorcery. 
 
The sad fact of the matter is that reliance on our brains’ skills of observation to tell us which medicines work and which don’t is a very dangerous path. It is precisely the path which led the physicians of old to utilize bloodletting as a primary form of treatment almost two thousand years. It’s not that the doctors of the past were stupid, negligent or malicious. They were simply told by a medical authority that draining their patients of a significant quantity of blood was an effective treatment. When they then employed this intervention many patients got better and they attributed this recovery to their treatment. It’s not that the bloodletting was actually helping these patients – quite the contrary - but some patients were bound to get better on their own anyways, and when they did, credit for their recovery was given to the bloodletting. This same error is made over and over by the physicians of today. 
 
Based on some weak theory or low-level evidence they prescribe a previously untested treatment. If that patient gets better, often the physician will prescribe it to all future patients with similar concerns, regardless of the outcome. We can all be agreed that this is dangerous, but what is the alternative? What should we be asking of our medical community instead?
 
The answer is trials – clinical trials, with many people that incorporate appropriate placebos and randomization. These trials may not be perfect, and occasionally they will promote an ineffectual therapy, but it is my strong opinion that these trials are far superior to the current reliance on personal observation. So please, demand that your physicians use medically researched treatments, instead of those that they’ve ‘seen’ work. Without this research, we’re really not all that far off from going back to bloodletting.