# Fully consistent condom use only 87% effective against HIV? **URL:** \ **Category:** Great Debates\ **Created:** [March 19, 2009, 6:39am UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999 "2009-03-19T06:39:11Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [March 19, 2009, 3:35pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/21 "2009-03-19T15:35:16Z")
> [@Really\_Not\_All\_That\_Bright](#): > > The 0.1% is for a single sexual encounter. As I’m sure is the 87% number. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 19, 2009, 3:42pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/22 "2009-03-19T15:42:42Z")
> [@Sage\_Rat](#): > > As I’m sure is the 87% number. Nuh uh. [QUOTE=mhendo] Note that the 87% figure for this study does NOT mean that, if a couple where one person is HIV+ have sex using condoms, they have a 13% chance of infecting the other partner. It means that the rate of transmission is 87% less than for couples where one partner is infected and condoms are not used. As the figures quoted in the abstract show, the 87% figure is found by comparing the transmission rates per 100 person-years for no-condom and always-condom use. [/QUOTE] ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [March 19, 2009, 3:48pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/23 "2009-03-19T15:48:17Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Nuh uh. _sigh_ The odds of transmission in one act of sex, without a condom is 0.1%. AKA 1 in 1000. The odds of transmission in one act of sex, with a condom is _87% less than it is without a condom_. The odds of transmission in one act of sex, _without a condom is 0.1%_. AKA 1 in 1000. “87% less” means the same thing as “13% of”. 13% of the rate of sex without a condom–0.1%–is 0.013%. AKA 1 in 8000. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 19, 2009, 3:57pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/24 "2009-03-19T15:57:04Z")
> [@Sage\_Rat](#): > > _sigh_ > > The odds of transmission in one act of sex, without a condom is 0.1%. AKA 1 in 1000. > The odds of transmission in one act of sex, with a condom is _87% less than it is without a condom_. > The odds of transmission in one act of sex, _without a condom is 0.1%_. AKA 1 in 1000. > “87% less” means the same thing as “13% of”. > 13% of the rate of sex without a condom–0.1%–is 0.013%. AKA 1 in 8000. I can handle arithmetic. Please don’t patronize me. Did you read the quote? Is it incorrect? ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [March 19, 2009, 4:12pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/25 "2009-03-19T16:12:12Z")
> [@Really\_Not\_All\_That\_Bright](#): > > I can handle arithmetic. Please don’t patronize me. > > Did you read the quote? Is it incorrect? My point is that **it is correct**. So I don’t see what problem you have with my math, because my math is based on what it says. Compounding the 0.1% base rate of transmission with the decrease of 13% is 0.013%. If you think the math is something other than 0.1% \* 13%, then I need to see what that math is, because otherwise I don’t know how you’re reading it that’s different from me. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [March 19, 2009, 4:17pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/26 "2009-03-19T16:17:08Z")
Ok , so what I get from the cite, is that indeed \*the **numbers** used \*ARE supported – it’s the conclusion reached/meaning assigned/spin given by the Church that’s questionable. 87% better may statistically be inferior to the theoretically achievable 100% better of , to turn around the phrase, “fully consistent abstinece” , but it is substantially better than nothing! And yes, the Church could be well advised, if that’s what the doctrine requires, to just continue to insist in that they absolutely oppose nonmarital sex and birth control on purely moral and spiritual grounds, and avoid resting on spinning statistics. What happens if/when someone invents a 99% safe and effective technology? Keep claiming it’s not perfect enough? ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 19, 2009, 4:29pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/27 "2009-03-19T16:29:53Z")
> [@Sage\_Rat](#): > > My point is that **it is correct**. So I don’t see what problem you have with my math, because my math is based on what it says. Compounding the 0.1% base rate of transmission with the decrease of 13% is 0.013%. If you think the math is something other than 0.1% \* 13%, then I need to see what that math is, because otherwise I don’t know how you’re reading it that’s different from me. The decrease is 87%, not 13%. And the point is that that figure is for 100 years of usage, not an individual encounter. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [March 19, 2009, 5:10pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/28 "2009-03-19T17:10:31Z")
> [@Really\_Not\_All\_That\_Bright](#): > > **panache45** is a she. (Right?) Wrong. Gay male, 60+ (63, I believe), monogamous for the last two decades, kilogamous[sup]\*[/sup] formerly… it’s not that hard to remember a few details on the odd fellow Doper here and there. > [@RNATB](#): > > Regardless of what distinctions anyone with half a brain might draw, **panache45** ’s post _is not snarky_. You’re just digging yourself a deeper hole. > > Take off the offenderati goggles and _read it_. _removes goggles_ I can see some plausible deniability there, certainly. What I can’t see is any attempt to answer the question in the OP. \*A neologism, I admit, but I think it’s not a bad one, at that. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 19, 2009, 5:14pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/29 "2009-03-19T17:14:56Z")
> [@Malacandra](#): > > I can see some plausible deniability there, certainly. What I can’t see is any attempt to answer the question in the OP That’s true. WRT remembering Doper details: there are 82,000 of us, you know. I rarely remember much about anybody, beyond the stuff that jumps out (ie., **Siam Sam** lives in Thailand, and so on.) ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [March 19, 2009, 5:16pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/30 "2009-03-19T17:16:25Z")
> [@Really\_Not\_All\_That\_Bright](#): > > The decrease is 87%, not 13%. It’s **effectiveness** is 87%. 87 times out of 100, it will be effective. Look at the sentence in the 3rd post, “Generally, the condom’s effectiveness at preventing HIV transmission is estimated to be 87%, but it may be as low as 60% or as high as 96%.” If we were talking about a sale at a supermarket, only paying 60% of the original price is really good. That’s a big sale. Still having to pay 96% of the original price though, that’s not much of a bargain. That’s a small sale. So why do they consider 60% to be low and 96% to be high? It’s because they’re saying that a 60% sale means that you get 60% off the original price and end up paying only 40%. And a 96% sale means that you only pay 4% of the original price. A hundred dollar widget costs $4. > [@](#): > > And the point is that that figure is for 100 years of usage, not an individual encounter. Ahah. Woops. :smack: ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [March 19, 2009, 5:51pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/31 "2009-03-19T17:51:56Z")
> [@Marienee](#): > > Possibly [here.](http://www.guttmacher.org/pubs/journals/3127299.html) > > In lab studies, of course, the transmission rate would be lower. Studies in the wild demonstrate that…lab studies do not necessarily translate to real life. Please note: The article linked by **Marienee** in this post is the same one i cited in post #3, but **Marienee** ’s link is better because you can get the whole article without a subscription. ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [March 19, 2009, 5:52pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/32 "2009-03-19T17:52:59Z")
> [@Malacandra](#): > > And you can ask it again and again, and you’ll likely find that rather than simply committing to having stopped or not stopped beating my wife, I’ll put you to the trouble of divining what I mean from what I’ve written. I’ve asked a Moderator if I may respond to this one point. Your post suggests that I have tried to trap you using the well-known logical fallacy implicit in the question ‘Have you stopped beating your wife?’. I have not done so, and it is unfair to suggest that I have. ‘Have you stopped beating your wife’ is a question that contains a hidden premise, namely that the addressee has ever beaten his wife. The question I asked you does not contain a hidden premise. I asked ‘Do you think it is important that people should only assert things that are objectively verifiable?’. **Malacandra** , I know you are entitled to ignore a question for whatever reason (e.g. if you feel unable to answer it). But it is neither fair nor honest to accuse me of employing logically fallacious questions when I have not done so. ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [March 19, 2009, 6:02pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/33 "2009-03-19T18:02:44Z")
> [@davekhps](#): > > But it’s Church teaching. > > Unfortunately, I think the Church makes a mistake in wading into the condom debate-- not because they’re technically right or wrong, but by their teaching, it’s a complete distraction from the message they wish to convey: sex outside of marriage is sinful. Not necessarily extreme fundamentalist “you’re going to burn in Hell” sinful, but in Church teaching, the only way to find grace is through a loving, monogamous marriage sanctified by the Church. Condoms could be _100%_ successful in all cases, and it still would be irrelevant, for Church teaching is that there should be no artificial birth control. But if you’re correct (and i believe you are), and even 100% condom efficacy wouldn’t be good enough for the Catholic Church, don’t you think it’s somewhat disingenuous of them to come out and declare that 87% “falls well short of an adequate means of disease prevention”? That is, by making the argument that 87% isn’t good enough, they imply that there is a figure that they _would_ consider acceptable. But we all know that they’re not going to change their minds even if we develop a 100% effective condom. So their weighing in on this debate really has nothing to do with the numbers anyway, and their assertion regarding the inadequacy of condoms is a complete red herring. ---
**Author:** ![alphaboi867](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alphaboi867/32/3898_2.png) [@alphaboi867](https://boards.straightdope.com/u/alphaboi867)\ **Post date:** [March 19, 2009, 9:13pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/34 "2009-03-19T21:13:33Z")
> [@davekhps](#): > > …Not necessarily extreme fundamentalist “you’re going to burn in Hell” sinful, but in Church teaching, the only way to find grace is through a loving, monogamous marriage sanctified by the Church… The Church considers fornication a mortal (as opposed to venial) sin. Anyone who dies without confessing and being absolved by a priest is therefore (perfect contrition aside) doomed to an eternity in Hell. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 19, 2009, 9:26pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/35 "2009-03-19T21:26:11Z")
> [@Sage\_Rat](#): > > It’s **effectiveness** is 87%. 87 times out of 100, it will be effective. Look at the sentence in the 3rd post, “Generally, the condom’s effectiveness at preventing HIV transmission is estimated to be 87%, but it may be as low as 60% or as high as 96%.” If it’s effective 87% of the time, that means the decrease is 87%. If it had an 87% failure rate, the decrease would be 13%. ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [March 19, 2009, 9:44pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/36 "2009-03-19T21:44:57Z")
I’m going to move this from General Questions to Great Debates. **Gfactor** General Questions Moderator ---
**Author:** ![Harriet\_the\_Spry](https://avatars.discourse-cdn.com/v4/letter/h/e56c9b/32.png) [@Harriet\_the\_Spry](https://boards.straightdope.com/u/Harriet_the_Spry)\ **Post date:** [March 19, 2009, 10:32pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/37 "2009-03-19T22:32:31Z")
> [@Really\_Not\_All\_That\_Bright](#): > > If it’s effective 87% of the time, that means the decrease is 87%. If it had an 87% failure rate, the decrease would be 13%. 1. The risk of pregnancy without birth control is roughly 80 per 100 person years. 2. The risk of pregnancy with always use of condoms is roughly 10 per 100 person years. (Similar numbers to items 1 and 2 are widely reported, often as “condoms have a 10% failure rate.”) 3. The risk of HIV transmission without condoms as reported in this study is about 7 per 100 person years. 4. The risk of HIV transmission with always use of condoms as reported in this study is about 1 per 100 person years. The 13% is attained by dividing the 1 in item 4 by the 7 in item 3. It is not at all the same number as the 10% in item 2. The 13% (or 87%) do not correspond to the way effectiveness of birth control is traditionally reported. This leads to confusion, which may be intentional to promote an anti-condom message, since most people don’t have much knowledge of statistics. ---
**Author:** ![begbert2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/begbert2/32/3357_2.png) [@begbert2](https://boards.straightdope.com/u/begbert2)\ **Post date:** [March 19, 2009, 11:12pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/38 "2009-03-19T23:12:11Z")
> [@Harriet\_the\_Spry](#): > > which may be intentional to promote an anti-condom message Naw, I’m _sure_ it was just an honest oversight. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [March 19, 2009, 11:15pm UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/39 "2009-03-19T23:15:49Z")
> [@ianzin](#): > > I’ve asked a Moderator if I may respond to this one point. > > Your post suggests that I have tried to trap you using the well-known logical fallacy implicit in the question ‘Have you stopped beating your wife?’. I have not done so, and it is unfair to suggest that I have. > > ‘Have you stopped beating your wife’ is a question that contains a hidden premise, namely that the addressee has ever beaten his wife. > > The question I asked you does not contain a hidden premise. I asked ‘Do you think it is important that people should only assert things that are objectively verifiable?’. > > **Malacandra** , I know you are entitled to ignore a question for whatever reason (e.g. if you feel unable to answer it). But it is neither fair nor honest to accuse me of employing logically fallacious questions when I have not done so. True. But my spidey-sense was screaming a warning that your question was loaded, such that there was a “Gotcha!” waiting whichever answer I offered. At times like that I often become quite obdurate. Well, then, in civility’s name: In general, yes, I do - and, to give one specific example, in the matter of condom use I should say it was extremely important. On the other hand, the Church is in the habit of making some assertions which are not objectively verifiable: God exists; He made his Word flesh; the Incarnate Word walked on the Sea of Galilee, transformed water into wine, raised the dead and was himself raised; and to those that received Him, He gave the power to become sons of God. The point is that someone who makes such statements ought not to be viewed as incapable of making the same kind of verifiable statements about mundane matters as you or I. It seems that when the RCC speaks about condom efficacy, it has grounds for doing so - and it is insulting to presume out of hand that it would not. ---
**Author:** ![DanBlather](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@DanBlather](https://boards.straightdope.com/u/DanBlather)\ **Post date:** [March 20, 2009, 2:22am UTC](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999/40 "2009-03-20T02:22:34Z")
> [@JRDelirious](#): > > What happens if/when someone invents a 99% safe and effective technology? Keep claiming it’s not perfect enough? Hell, by Church doctrine even being a virgin doesn’t prevent you from getting knocked up. [Previous page](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999.md?page=1) [Next page](https://boards.straightdope.com/t/fully-consistent-condom-use-only-87-effective-against-hiv/489999.md?page=3)