How valid are those statistics? Lots of medical procedures are just estimates. And it’s not like the outcomes are random so that <1% bad outcome with unknown c

How valid are those statistics? Lots of medical procedures are just estimates. And it’s not like the outcomes are random so that <1% bad outcome with unknown causes could be 100% for a gene she has. Her fear isn’t completely irrational as perhaps her stats knowledge is useful to not assume perfect estimation of those odds. I always found it interesting how people assume numbers are spot on when they are frequently just estimates or averages of multiple experts guessing.