PrEP treatment also mandates regular STI testing. I wonder if it's possible to control for the higher diagnosis rate (e.g. would have been infected anyways just

PrEP treatment also mandates regular STI testing. I wonder if it's possible to control for the higher diagnosis rate (e.g. would have been infected anyways just now know about it). And what is a comparable rate for the same population pre-PrEP?