Hospital cutting top-class medication that's on the rise (6)
I believe the answer is:
Here is my best explanation:
'the rise' is the definition.
(uphill is a kind of rise)
'hospital cutting top-class medication that's on' is the wordplay.
'hospital' becomes 'h'.
'cutting' means one lot of letters goes inside another (some letters cut their way into a word).
'top-class' becomes 'u' (as in U and non-U speech).
'medication' becomes 'pill' (pill is a kind of medication**).
'that's on' says to put letters next to each other.
'h' inserted inside 'upill' is 'UPHILL'.