That's true for various reasons such as benefits expectations (some of it the result of union negotiations historically) and tax effects. [1] There's also the theory, which may not be especially true as I understand it, that preventative medicine like regular physicals can cut healthcare costs down the road. In any case though, I'm pretty sure that annual physicals and the occasional stitches or urgent care visit aren't huge contributors to overall healthcare costs.

[1] And certainly things like dental insurance are pretty much just "extended warranties" rather than insurance against catastrophic expenses.