Question about condom safety out of general interest

[Mediapd]

So whenever it is said that condoms have a 98% efficacy rate on perfect use over a year, does that 2% have condom breakage despite perfect use or is it unknowingly so, and how are they able to even measure that it was perfectly used in the first place? Humans aren’t perfect I wouldn’t expect all these people in experiments to be perfect either, there has to be some margin of human error within statistic. I guess my question is, with condom usage if the condom never breaks or slips off there can’t be any risk of pregnancy or STD besides the ones condoms don’t prevent

[Jacob]

Heya,

Firstly yes you're correct, condoms fail by coming off or breaking.

Perfect use means the folks consistently always used a condom correctly to the best knowledge of the participants and the researchers. Something still needs to give for a condom to break, but the causes will be things that neither the user or researchers were able to predict, nor able to know or assess after the fact. E.g. it's going to be hard to know if a manufacturing/storage-related defect caused a breakage when the thing is already broken, and probably thrown away. There's also no way to account for someone forgetting a step, and forgetting that they forgot a step.

"Perfect" is maybe better understood as shorthand for "As perfect as we could have expected, to the best of the knowledge of the researchers and the participants at the time." - Given that none of us would be able to predict or know those points of failure it's also as "perfect" as we could ever expect from ourselves, and that allows us to make more informed decisions about using a 2nd method, and having a plan for unwanted pregnancy.

Maybe another way to look at it that the pregnancy rate in "imperfect/typical" includes known errors and pregnancy with "perfect" is mostly due to unknown errors/factors.

Does that help?

[Mediapd]

Yes that makes sense and I get it now, I had always just assumed that that 2% were just people that had absolutely no clue at all there was something wrong but had just ended up pregnant or something