Nurse accepting doctor's conclusion and direction (5)
I believe the answer is:
Here is my best explanation:
'direction' is the definition.
(trend is a kind of direction)
'nurse accepting doctor's conclusion' is the subsidiary indication.
'nurse' becomes 'tend' (I've seen this before**).
'accepting' indicates putting letters inside.
'conclusion' says to take the final letters.
The last letter of 'doctor' is 'r'.
'tend' enclosing 'r' is 'trend'.
'and' is the link.
(Other definitions for trend that I've seen before include "General line of orientation", "Mode", "Prevailing tendency", "General direction or fashion", "Direction, tendency", "be all over Twitter, Instagram, etc", "Bias", "Fashion; general drift", "General direction of change" and "General direction in which something is developing".)