AMBOSS uses both. My logic is that as prevalence increases, fewer people remain at risk (since some are already diseased).
The denominator (1āP) adjusts for that.
I would say we merge these two cards and keep the more simple equation
What is the relationship between prevalence and incidence? prevalence / (1 - prevalence) = {{c1::incidence * average duration of disease}} 1485736698405
How are prevalence and incidence related? {{c1::Prevalence = Incidence Ć Duration}} 1495670123090
@Ahmed7 does this qualify as a dupe?
Yes, or we can see how else to modify these cards. You can either set up a vote in Slack or @Jwill can handle the dupe voting (we do it around every Tuesday on Slack, if you scroll up in Slack youāll see the previous ones)
Iāve been really bad about it of late 
but @schralp you can post it in slack (preferably in the same format I usually follow) or DM me the nids in slack and Iāll add them to my running dupe list to be addressed!
@Jwill @schralp did we ever finalize this? Number of suggestions open here that have sufficient upvotes to merge but would need parity between the two cards yāall were discussing. Alternative would be to do as suggested in an earlier suggestion and make this one ask specifically for āin rare diseasesā. Would be a simpler fix imo
I might be the remembering this wrong but I donāt recall getting enough votes. I think this would be a better approach for now: