Prep 92% Effectiveness & Causes of the 8% risk factor

[Pitt1988]

Hey Guys

So i keep seeing prep is 92% effective; as a 25 year old addicted to bb porn (yes thats where most of us got our interest in BB in the first place) im contemplating getting on prep, but im trying to understand what the 8% chance entails, or what are the causes why prep is not say.... 99% effective, and im also curious as to who is more affected by that 8% tops or bottoms? anyone got any info as to this topic, thanks

[rawfuckr]

Hey Guys

So i keep seeing prep is 92% effective; as a 25 year old addicted to bb porn (yes thats where most of us got our interest in BB in the first place) im contemplating getting on prep, but im trying to understand what the 8% chance entails, or what are the causes why prep is not say.... 99% effective, and im also curious as to who is more affected by that 8% tops or bottoms? anyone got any info as to this topic, thanks

Efficacy depends on how often you take it. If you take it daily efficacy is 99% to 100%. In a recent study, no one taking the pill 7 days a week seroconverted ( http://goo.gl/OYbi5f ) The 92% number could be from less adherence, or from different ways of looking at the data. Real world data now shows very high efficacy (+99%) with perfect adherence (taken daily).

Edited August 10, 2014 by rawfuckr

[Pitt1988]

Thanks for explaining it all to my bud, ive been following prep for at least 2 years now, and i noticed everytime there was an article or information it first started staing 72% effective, then it went up to 92%, ive always taught that 8% risk factor had something to do with sex, for example, if you had sex with someone that just seroconverted and has a high viral load, or maybe you took too many loads; not adherence... now im fully informed of the matter, thanks

[seaguy]

Well as with all anal sex the bottom is most at risk if that is what you meant by who is more affected.

[Guest JizzDumpWI]

PrEP though doesn't change effectiveness by how often you're fucked, or by the serostatus of who fucks you. It depends upon compliance to taking your meds. Bottoms well advised to take it daily. Even a 1% risk is hugely better than condom sex and/or serosorting.

[fskn]

PrEP though doesn't change effectiveness by how often you're fucked, or by the serostatus of who fucks you. It depends upon compliance to taking your meds.

Looking at it from a different angle, calculating risk reduction in the medical studies very much depends on frequency of sex, positin (top/bottom), and partner HIV status. For example, if a participant had no risky sex during a study, PrEP didn't prevent him from becoming infected. On the other hand, if a participant who reported bottoming for numerous Poz or unknown-status guys remained HIV-negative, PrEP (plus anti-retrovirals used by some of the known-Poz tops) had a strong protective effect.

That is why the original iPrEx study quoted two risk reduction percentages for participants who adhered:

92% unadjusted

95% adjusted for sexual risk behavior

My theory is that shame leads us to under-report risky sexual behavior. If this is true, then the 95% figure was an underestimate.

In any case, the point is moot now because, as noted earlier in this thread, the more recent iPrEx OLE study found 100% risk reduction with good adherence. iPrEX OLE used very sophisticated techniques to check adherence, which, as you say, is the critical variable.

Understanding the efficacy of Truvada for PrEP is simple: no medication works if you don't take it!

[bttm79]

Can you please post the link to the study that you are referencing?

[drscorpio]

http://www.iprexole.com/1pages/prep/prep-whatistheiprexstudy.php

[rawTOP]

So i keep seeing prep is 92% effective; as a 25 year old addicted to bb porn (yes thats where most of us got our interest in BB in the first place) im contemplating getting on prep, but im trying to understand what the 8% chance entails

The bottom line is that condoms are only about 92% effective as well. So if you think condom sex is safe sex, then sex on PrEP is also safe sex.