EBM, precision medicine: literal but more

Often the metaphorical meaning of a word is used more often than the literal one.

Medicine is a technical domain, but lots of terms in it are metaphorical.

EBM, or evidenced based medicine, is a label for a suggested desire to literally base medical practice on evidence rather than 'what you've always done'. Does extra sugar intake cause hyperactivity in children? It's pretty obvious it does. Except when studies are done, there is no appreciable difference in activity afterwards between children ingesting more sugar and those who don't.

We have preconceived plausible notions, but it's always good to check more scientifically. Isn't medicine always working on evidence, and equally dismissive of unscientific, non-evidenced based things like homeopathy, or ingrained myths like feed a cold starve a fever? Of course, but still there are reasonable plausible things that just may not have an actual effect. EBM came to refer to a trend in RCT, randomized controlled trials, which means a trend in a particular kind of government funding. Also it became associated with expensive measures to confirm really idiotically obvious things and parodied by the idea of an RCT for the efficacy of parachutes. So sometimes EBM sounds like a good thing, and sometimes it sounds like a dumb thing. But it mostly means 'be skeptical, do an RCT', whatever the nuances of funding and sample size are.

Personalized medicine, as a term, is also problematic. Literally it's saying medicine should be directed towards the individual differences. But that's so obvious, you're not going to treat someone for a broken left arm when it's their right that's broken. How people use the term 'personalized medicine' nowadays is for when gene variations are known about the patient. That's it. PM, the non-literal version, is for the handful of medical situations where the different gene variation (on a small set of genes) suggests a slightly different therapy. The expectation is that the science will expand to include lots of gene variations and problems. Yes, doctors have been using medicine personalized to a patient's family history, environment, social situation, problem itself (duh!), etc. forever. PM currently refers to doing that same thing but with some gene knowledge.

These two terms, EBM and personalized medicine, are not incorrect, but they have a much more specific meaning than you think if you've never heard them before. If you use them all the time, then you (implicitly or not) know their narrow usage. Luckily people whether they know it or not, don't use these in the broader situations.