follow-up vs scrutiny

follow-up and scrutiny both are nouns.

Word	Noun	Adjective	Verb	Adverb
follow-up	Yes	No	No	No
scrutiny	Yes	No	No	No

As nouns, scrutiny is a hypernym of follow-up; that is, scrutiny is a word with a broader meaning than follow-up:

follow-up: a subsequent examination of a patient for the purpose of monitoring earlier treatment
scrutiny: the act of examining something closely (as for mistakes)

Other hypernyms of follow-up include examination.

follow-up (noun)	scrutiny (noun)
a subsequent examination of a patient for the purpose of monitoring earlier treatment	the act of examining something closely (as for mistakes)
an activity that continues something that has already begun or that repeats something that has already been done	a prolonged intense look
a piece of work that exploits or builds on earlier work