Finding conferences in subject area (Medical Informatics) I am struggling to find conferences in my subject area, preferably in Western Europe. My supervisor tends to be otherwise very busy and is poor at actually providing this information in practice.

My area isn't terribly niche: it concerns text mining of medical information (therefore straddling both medical informatics and computer science).

Is there a website that contains lists of informatics conferences? Or a particular avenue that one should ideally use when looking for conferences in this area?
Is this anything like what you're looking for?

Doing some searching of my own, I definitely ran across the problem you mention -- the lists of events in your field are often out of date. So, while there are sites that list conferences by discipline, they might not work very well for you (the one linked above being a tentative exception). This might partially be peculiar to your field, though it does appear in others as well. 

However, part of the problem might also lie within search patterns. Hybrid topics are often hard to search successfully due to conflagration of terms, and it seems this remains true for hybrid disciplines.

If you're not already familiar with them, it's definitely a good idea to acquaint yourself with Google's search operators; they can significantly ease your search-related challenges. My favorite is the tilde (~), which when placed before a term includes results with synonyms -- very useful.

Searching like this, I was able to find some individual conferences which seem to have their call for submission still open. (I know little to nothing about your particular field, so if I got these wrong, I apologize):


http://www.imia-medinfo.org/new2/events
http://datamining.conferenceseries.com/call-for-abstracts.php (track
3 on the page)
http://www.kdd.org/kdd2016/calls