In addition to the practical tests you mention (which I wouldn't worry too much about, if I were you - just take it as it comes, and do your best on the day), don't be surprised if you get asked to explain your motivation for wanting to join the "healthcare sector".
That might sound like a daft question, but actually it's not.
If I were on the interview panel (but don't worry, I won't be) I would be more interested in a guy's personal qualities than technical background (especially for a trainee position). As in:- "it is likely that the guy will stay the course"?
And (as Sean has just mentioned), my old favourite:- willingness to work!
Good luck.
