Anecdotal evidence has a very important role in medical science.
Nonsense
“The expression anecdotal evidence refers to evidence from anecdotes. Because of the small sample, there is a larger chance that it may be unreliable due to cherry-picked or otherwise non-representative samples of typical cases.[1][2] Anecdotal evidence is considered dubious support of a claim; it is accepted only in lieu of more solid evidence. This is true regardless of the veracity of individual claims.”
Double blind studies are considered important in medicine