Considering the widespread misconceptions about condom efficacy rates, that they’ve made a decently effective alternative more affordable is excellent news!
If you are not familiar with the misconceptions, I will briefly explain:
The condom boxes say there’s a 2% failure rate. That’s 2% per year. Considering that most people are sexually active for far more than one year, that 2% rate is completely meaningless.
Furthermore, that’s for perfect use. The actual way people use condoms, the rate of failure can be (an average of) 15% per year.
I tried finding studies on condoms that ran longer than one year, but couldn’t find any. However, a survey was done that gives us an idea of the aftermath of this:
“Three hundred four women (78%) had used condoms for an aggregate total of 1178 years (average=3.9 years per woman; range=1 month-25 years). Seventy-eight women (25.6%) reported becoming pregnant while using condoms”
In not even four years, more than one in four of them became pregnant.
Unfortunately, this information is likely to cause anyone reading it to be at an evolutionary disadvantage, therefore it may make sense to spread the word as much as possible and remember to tell people who are dissimilar to yourself.
The condom boxes say there’s a 2% failure rate. That’s 2% per year. Considering that most people are sexually active for far more than one year, that 2% rate is completely meaningless.
Do people actually interpret that 2% to mean 2% per lifetime? If I didn’t know what it meant, I’d interpret it as 2% per intercourse.
That’s what I assumed as well, that it was 2% per incident, but I’m having a little trouble parsing those differently:
How is 2% per incident different than 2% per year? I’d interpret both of those statements as ‘on average, given perfect use, a condom will be ineffective at preventing pregnancy in one use out of fifty’.
Well, yes, but what does 2% failure rate per year even mean when it’s presented independent of a number of uses per year? I mean, without knowing what number of average uses were used to calculate “2% failure rate per year”, it seems like somewhat of a misleading statement, as I’m reasonably certain (let’s say at least 90%) that it’s not intended to reflect that condoms become more protective the more chances you have to use them.
I feel like I’m missing something basic here that would let me see why it’s a useful piece of information on its own.
what does 2% failure rate per year even mean when it’s presented independent of a number of uses per year
This is a good observation. You can look up what the average number of uses per year is. If I remember right, I’ve seen some condom efficacy studies include that information.
I feel like I’m missing something basic here that would let me see why it’s a useful piece of information on its own.
You’re not missing anything basic, you’re correctly perceiving ambiguity where ambiguity does exist. Even when information is really important, I’ve found that it’s often been omitted simply because products are marketed to the average person, not to nerdy people like me, and most people don’t want to think as much as I do. For this reason, I’ve found it’s very important to be careful not to assume that the world is doing sensible things or giving me all the information. They’re not just leaving information out, they’re also not being held accountable by a world full of people who think as much as I do. Therefore, they can get away with slapping various nonsense marketing claims and out-of-context data on their boxes without people questioning them.
Thanks for taking a moment to let me know that my comment is appreciated and that this information makes a difference for you. I find that, like Luke says in The Power of Reinforcement, knowing that a behavior of mine has made a difference and is wanted “increases the probability that the behavior will occur again”.
I think LessWrong could really use more positive reinforcement, so I hereby positively reinforce you for showing the humility to positively reinforce.
I agree it’s misleading. That’s why I’d prefer a metric like this, where the precise definitions you use don’t matter if they are the same in both the numerator and the denominator as constant factors would cancel out.
Let’s say, hypothetically speaking, that the average number of uses per year is 100.
A 2% per incident risk will add up to a yearly 50% risk for the average user.*
A 2% per year risk already included 100 uses, so it is still 2% per year.
A 2% per year risk would add up to a 70% chance over the 35 or so years women are fertile and active and a 2% per incident risk would add up to a much, much higher risk, likely resulting in multiple pregnancies.*
* This is only if pure math reflects reality, which it probably doesn’t because there are other factors here like people forgetting important parts of the instructions over time, people getting better at using them over time, or people becoming sloppy about applying them because they’re tired of them or have developed a sense of over-confidence.
No, it requires that the failures of condom usage be independent events from one another. That is to say, that person A using a condom at time B has the same probability of failure as person C using a condom at time D, even if C=A or B=D.
Without knowing more, it is entirely possible that some fraction of men have supersperm which gets through condoms and that they account for all the failures, and those that use condoms but avoid supersperm will never fail. Alternatively it is possible that some group of people keep making the same mistakes and account for all the failures while another group of people use them right and don’t fail.
Math can be used to analyze all of these possibilities.
The 15% “typical use” failure rate is the failure rate for people who use condoms most of the time. I’m disinclined to call it a failure of condoms myself that they don’t work when people don’t use them, though perhaps it could be considered a defect in the method that people apparently have such trouble using them all the time. Do note that birth control research does not involve researchers observing people in their bedrooms to see how and how consistently they are using their methods. The research is based on people’s reported use, so since those reports are obviously not perfectly reliable, the 2% “perfect use” failure rate almost certainly is also partly (perhaps mostly) due to occasional failures to use the condoms.
In IT, if people don’t use your software correctly, it’s called “Bad user interface design.” In business, if people don’t like your product enough to actually use it, it’s considered your responsibility to make a better product next time. Most people are blaming the condom users, but I think we can take the outside perspective instead. Instead of “shoulding” the condom users, let’s criticize the product:
You have to remember the product when? This is kinda bad timing to remember stuff, you know?
They have to carefully concentrate and use agile finger motions at that time? Maybe they are so excited that fine motor skills like putting on a condom become really hard due to shaking fingers, or concentration becomes a problem due to distraction, and they put it on wrong.
They have to use impulse control then? Maybe their neuro-chemistry is all bent out of shape and impulse control is low. This is kinda a bad time to expect excellent impulse control, seriously.
Maybe they spent a lot of time getting themselves or their partners ready to go, and they know that a delay can deflate the mood, so they feel conflicted about doing things like reading the instructions, taking their time putting it on, or just getting the thing out.
Please do not confuse this message for “don’t use condoms”. My message is actually “We need something better than just condoms.” (Even if condoms were a joy to use, their effectiveness is still too low.) More importantly:
Please consider also that if there’s any trait at all that makes using condoms less likely to succeed (lower impulse control, less agile fingers, memory issues) those traits may have a genetic advantage for as long as condoms are a primary method of contraception. Example: If you keep forgetting to use your condoms, you’re more likely to get someone pregnant, and if the memory issue is genetic, you’ve just put one more copy of that gene into the world.
To prevent their companies from having a negative impact on the gene pool, and because the consequences for their customers can be so dire (moreso for a pro-life couple who isn’t ready for a baby), I think contraceptive makers should take more responsibility here.
IT people do it. Other business people do it. They can do it, too.
Replacing condoms doesn’t work for people who aren’t currently in monogamous relationships. We need them to protect against STIs. Encouraging people to entirely replace condoms would I should think lead to an increase in STIs.
I’ve used condoms every single time I’ve had sex, and they’ve only failed twice. Both of the times they failed I took emergency contraception. I’ve never had a pregnancy scare. Of course I could be infertile, but many of my friends use the same method, and they find it effective. Others use a combination of hormonal contraception and condoms.
I’m torn here. Do I tell you that’s a good point because combination strategies can be much more effective at preventing pregnancy, or do I let you know that the efficacy rate for STIs are subject to the same forces as the efficacy rates for pregnancy?
I guess I can do both. You’ll decide what risk to take in any case.
The amount of protection that you can get from a condom against STIs is not as good as the amount of protection you get against pregnancy. Not everyone can give you an STI (about 20% of the population) whereas most straight couplings can lead to pregnancy (about 90% of people of childbearing age are fertile). So that increases your odds of a good outcome. Some people are honest about their STI status, and that also increases your odds of a good outcome—but don’t forget that some people do not even know that they have an STI, and others may be in denial or crazy or sociopathic—and if you’re having casual sex, you really can’t be sure about a person’s moral character and sanity level.
Your chance of getting an STI while using a condom would be a lot higher than 50% if you had a partner with a disease for the rest of your life. If you have random partners, and 1⁄20 people has an STI and some of them don’t know it, and some of them aren’t honest… I’m not sure what your chances are, but if you’re successful with finding partners, it could be substantially worse than a 2% lifetime risk.
You may want to try looking up rates of STI among people who have non-relationship sex.
Another possibility is to find a special friend and get tested together.
If that won’t work, a combination strategy (like condoms with spermicide) could be a significant improvement. You may want to research nonoxynol-9 before using it. I’ve heard that it increases the chance of disease transmission.
Pretty much all the non monogamous people I know get regular tests. So yes, most people use testing in addition to condoms. I don’t have casual sex any more, really, but I never caught an STI when I did.
Oh, and most condoms sold in the UK contain spermicide.
Okay, I understand your alarm—you’re probably thinking something along the lines of WTF, you’re saying condoms aren’t effective, why are you contradicting sex ed? If you want one quick reference to show you why you should be concerned about this, the Journal of Family Practice published a research survey that revealed the aftermath of these condom myths. I added it to the comment you were responding to. As for why I said what I said in the last comment: I tried finding a condom study that ran for longer than a year. I couldn’t find one anywhere. The one year studies gave failure rates that ranged between 2% and 15%. Those figures can be found at Pubmed if you search for condom efficacy.
Indeed! Even assuming I’m somewhat better than typical, condoms make me a bit nervous.
Considering that most people are sexually active for far more than one year, that 2% rate is completely meaningless.
(Frivolous nitpicking) Yeah, but I think it’s probably one of the better units of measure they could have chosen. “Per intercourse event” would probably be so low that people wouldn’t grok the fact that their overall chances were much worse. But any unit more than a year doesn’t make much sense.
I suppose, like, five or ten years might make sense. But it seems to me that the length of people’s sex lives and time of usage of different birth control methods vary enough that even that could be overkill. Like, if you try out a method for a few months to a year, the 5-year prognosis won’t necessarily be relevant to you. Although I suppose you wouldn’t necessarily plan to use a method for less than 5 years, in which case, that’s what would be relevant to your decision making, even if you don’t end up using it for that long.
The problem is, people are mistaking them for lifetime rates, and they are not. If people are trying to use them as lifetime rates when they’re not, then that’s just not going to work.
Considering the widespread misconceptions about condom efficacy rates, that they’ve made a decently effective alternative more affordable is excellent news!
If you are not familiar with the misconceptions, I will briefly explain:
The condom boxes say there’s a 2% failure rate. That’s 2% per year. Considering that most people are sexually active for far more than one year, that 2% rate is completely meaningless.
Furthermore, that’s for perfect use. The actual way people use condoms, the rate of failure can be (an average of) 15% per year.
I tried finding studies on condoms that ran longer than one year, but couldn’t find any. However, a survey was done that gives us an idea of the aftermath of this:
“Three hundred four women (78%) had used condoms for an aggregate total of 1178 years (average=3.9 years per woman; range=1 month-25 years). Seventy-eight women (25.6%) reported becoming pregnant while using condoms”
In not even four years, more than one in four of them became pregnant.
http://www.jfponline.com/Pages.asp?AID=2603
Unfortunately, this information is likely to cause anyone reading it to be at an evolutionary disadvantage, therefore it may make sense to spread the word as much as possible and remember to tell people who are dissimilar to yourself.
Do people actually interpret that 2% to mean 2% per lifetime? If I didn’t know what it meant, I’d interpret it as 2% per intercourse.
Yes, unfortunately, a large number of the people I’ve talked to do interpret it as 2% per lifetime.
That’s what I assumed as well, that it was 2% per incident, but I’m having a little trouble parsing those differently:
How is 2% per incident different than 2% per year? I’d interpret both of those statements as ‘on average, given perfect use, a condom will be ineffective at preventing pregnancy in one use out of fifty’.
I guess the average condom user uses more than one per year.
Well, yes, but what does 2% failure rate per year even mean when it’s presented independent of a number of uses per year? I mean, without knowing what number of average uses were used to calculate “2% failure rate per year”, it seems like somewhat of a misleading statement, as I’m reasonably certain (let’s say at least 90%) that it’s not intended to reflect that condoms become more protective the more chances you have to use them.
I feel like I’m missing something basic here that would let me see why it’s a useful piece of information on its own.
This is a good observation. You can look up what the average number of uses per year is. If I remember right, I’ve seen some condom efficacy studies include that information.
You’re not missing anything basic, you’re correctly perceiving ambiguity where ambiguity does exist. Even when information is really important, I’ve found that it’s often been omitted simply because products are marketed to the average person, not to nerdy people like me, and most people don’t want to think as much as I do. For this reason, I’ve found it’s very important to be careful not to assume that the world is doing sensible things or giving me all the information. They’re not just leaving information out, they’re also not being held accountable by a world full of people who think as much as I do. Therefore, they can get away with slapping various nonsense marketing claims and out-of-context data on their boxes without people questioning them.
Yeah, this is good advice in general, and it’s definitely what I was doing wrong this time.
Thanks for taking a moment to let me know that my comment is appreciated and that this information makes a difference for you. I find that, like Luke says in The Power of Reinforcement, knowing that a behavior of mine has made a difference and is wanted “increases the probability that the behavior will occur again”.
I think LessWrong could really use more positive reinforcement, so I hereby positively reinforce you for showing the humility to positively reinforce.
You’re welcome.
I agree it’s misleading. That’s why I’d prefer a metric like this, where the precise definitions you use don’t matter if they are the same in both the numerator and the denominator as constant factors would cancel out.
Here’s how 2% per incident is different:
Let’s say, hypothetically speaking, that the average number of uses per year is 100.
A 2% per incident risk will add up to a yearly 50% risk for the average user.*
A 2% per year risk already included 100 uses, so it is still 2% per year.
A 2% per year risk would add up to a 70% chance over the 35 or so years women are fertile and active and a 2% per incident risk would add up to a much, much higher risk, likely resulting in multiple pregnancies.*
* This is only if pure math reflects reality, which it probably doesn’t because there are other factors here like people forgetting important parts of the instructions over time, people getting better at using them over time, or people becoming sloppy about applying them because they’re tired of them or have developed a sense of over-confidence.
No, it requires that the failures of condom usage be independent events from one another. That is to say, that person A using a condom at time B has the same probability of failure as person C using a condom at time D, even if C=A or B=D.
Without knowing more, it is entirely possible that some fraction of men have supersperm which gets through condoms and that they account for all the failures, and those that use condoms but avoid supersperm will never fail. Alternatively it is possible that some group of people keep making the same mistakes and account for all the failures while another group of people use them right and don’t fail.
Math can be used to analyze all of these possibilities.
I think the figure you’re looking for is 1 - (0.98^100) = 0.87 (assuming no-one gets pregnant twice in the same year).
Well if you have sex once per year, it is not different.
My condolences.
The 15% “typical use” failure rate is the failure rate for people who use condoms most of the time. I’m disinclined to call it a failure of condoms myself that they don’t work when people don’t use them, though perhaps it could be considered a defect in the method that people apparently have such trouble using them all the time. Do note that birth control research does not involve researchers observing people in their bedrooms to see how and how consistently they are using their methods. The research is based on people’s reported use, so since those reports are obviously not perfectly reliable, the 2% “perfect use” failure rate almost certainly is also partly (perhaps mostly) due to occasional failures to use the condoms.
In IT, if people don’t use your software correctly, it’s called “Bad user interface design.” In business, if people don’t like your product enough to actually use it, it’s considered your responsibility to make a better product next time. Most people are blaming the condom users, but I think we can take the outside perspective instead. Instead of “shoulding” the condom users, let’s criticize the product:
You have to remember the product when? This is kinda bad timing to remember stuff, you know?
They have to carefully concentrate and use agile finger motions at that time? Maybe they are so excited that fine motor skills like putting on a condom become really hard due to shaking fingers, or concentration becomes a problem due to distraction, and they put it on wrong.
They have to use impulse control then? Maybe their neuro-chemistry is all bent out of shape and impulse control is low. This is kinda a bad time to expect excellent impulse control, seriously.
Maybe they spent a lot of time getting themselves or their partners ready to go, and they know that a delay can deflate the mood, so they feel conflicted about doing things like reading the instructions, taking their time putting it on, or just getting the thing out.
Please do not confuse this message for “don’t use condoms”. My message is actually “We need something better than just condoms.” (Even if condoms were a joy to use, their effectiveness is still too low.) More importantly:
Please consider also that if there’s any trait at all that makes using condoms less likely to succeed (lower impulse control, less agile fingers, memory issues) those traits may have a genetic advantage for as long as condoms are a primary method of contraception. Example: If you keep forgetting to use your condoms, you’re more likely to get someone pregnant, and if the memory issue is genetic, you’ve just put one more copy of that gene into the world.
To prevent their companies from having a negative impact on the gene pool, and because the consequences for their customers can be so dire (moreso for a pro-life couple who isn’t ready for a baby), I think contraceptive makers should take more responsibility here.
IT people do it. Other business people do it. They can do it, too.
Replacing condoms doesn’t work for people who aren’t currently in monogamous relationships. We need them to protect against STIs. Encouraging people to entirely replace condoms would I should think lead to an increase in STIs.
I’ve used condoms every single time I’ve had sex, and they’ve only failed twice. Both of the times they failed I took emergency contraception. I’ve never had a pregnancy scare. Of course I could be infertile, but many of my friends use the same method, and they find it effective. Others use a combination of hormonal contraception and condoms.
I’m torn here. Do I tell you that’s a good point because combination strategies can be much more effective at preventing pregnancy, or do I let you know that the efficacy rate for STIs are subject to the same forces as the efficacy rates for pregnancy?
I guess I can do both. You’ll decide what risk to take in any case.
The amount of protection that you can get from a condom against STIs is not as good as the amount of protection you get against pregnancy. Not everyone can give you an STI (about 20% of the population) whereas most straight couplings can lead to pregnancy (about 90% of people of childbearing age are fertile). So that increases your odds of a good outcome. Some people are honest about their STI status, and that also increases your odds of a good outcome—but don’t forget that some people do not even know that they have an STI, and others may be in denial or crazy or sociopathic—and if you’re having casual sex, you really can’t be sure about a person’s moral character and sanity level.
Your chance of getting an STI while using a condom would be a lot higher than 50% if you had a partner with a disease for the rest of your life. If you have random partners, and 1⁄20 people has an STI and some of them don’t know it, and some of them aren’t honest… I’m not sure what your chances are, but if you’re successful with finding partners, it could be substantially worse than a 2% lifetime risk.
You may want to try looking up rates of STI among people who have non-relationship sex.
Another possibility is to find a special friend and get tested together.
If that won’t work, a combination strategy (like condoms with spermicide) could be a significant improvement. You may want to research nonoxynol-9 before using it. I’ve heard that it increases the chance of disease transmission.
Pretty much all the non monogamous people I know get regular tests. So yes, most people use testing in addition to condoms. I don’t have casual sex any more, really, but I never caught an STI when I did.
Oh, and most condoms sold in the UK contain spermicide.
Please cite your sources for those numbers, they look like the ridiculously fudged one Catholic sources come up with.
Okay, I understand your alarm—you’re probably thinking something along the lines of WTF, you’re saying condoms aren’t effective, why are you contradicting sex ed? If you want one quick reference to show you why you should be concerned about this, the Journal of Family Practice published a research survey that revealed the aftermath of these condom myths. I added it to the comment you were responding to. As for why I said what I said in the last comment: I tried finding a condom study that ran for longer than a year. I couldn’t find one anywhere. The one year studies gave failure rates that ranged between 2% and 15%. Those figures can be found at Pubmed if you search for condom efficacy.
Indeed! Even assuming I’m somewhat better than typical, condoms make me a bit nervous.
(Frivolous nitpicking) Yeah, but I think it’s probably one of the better units of measure they could have chosen. “Per intercourse event” would probably be so low that people wouldn’t grok the fact that their overall chances were much worse. But any unit more than a year doesn’t make much sense.
I think a decent measure would be P(getting pregnant|one intercourse with condom)/P(getting pregnant|one intercourse without condom).
Do you really think the average person being/needing information about condoms can understand that?
If worded as “Using a condom reduces the chances of getting pregnant by X%” or “by N times”, probably.
Good for you. They should make everybody nervous!
It would be more accurate to reality, and would aid people in family planning. What about this does not make sense?
I suppose, like, five or ten years might make sense. But it seems to me that the length of people’s sex lives and time of usage of different birth control methods vary enough that even that could be overkill. Like, if you try out a method for a few months to a year, the 5-year prognosis won’t necessarily be relevant to you. Although I suppose you wouldn’t necessarily plan to use a method for less than 5 years, in which case, that’s what would be relevant to your decision making, even if you don’t end up using it for that long.
The problem is, people are mistaking them for lifetime rates, and they are not. If people are trying to use them as lifetime rates when they’re not, then that’s just not going to work.