what's a pre employment medical examination level 1 in uk? are they also supposed to draw blood for analysis?

Answer 1

Why ?

It's cheaper to check your urine & hair samples ...

Answer 2

I don't think there are any set levels - the level that you refer to must have been set by either the employer or their insurer.

I doubt they'd take a blood sample though - I bet it will just be a very basic health check. Unless you work in a sector where they might need to know the kind of things that a blood test would bring up.