agapewolf:
I’m testing a tent’s ability to keep me dry, over 100 days, and it rains only 25 of those days. Well, I get wet on those 25 days. Can I honestly say that the tent is 75% likely to keep me dry and 25% likely to fail? Of course not! This is the exact same thing.
Agapewolf, although you can’t say that the tent is 75% likely to you keep you dry (which, as you correctly point out, relies on the actual weather data), you
can say that if you use the tent you have a 25% chance of getting wet. This happens to be the same chance you’d have of getting wet if you had not been using any tent at all, thus demonstrating how ineffective the tent actually is.
Most current published contraceptive efficacy data is phrased in terms of population “failures.” In other words, if 100 people used method x for one year, how many of them would experience and unintentional pregnancy? This information can then be compared to other methods or to no method. So, for example, we know that for every 100 women, 85 of them should become pregnant within one year if they are having regular intercourse and not trying to prevent pregnancy. (Or, to continue with your analogy, there’s an 85% chance you’ll get wet if you’re regularly sleeping outside and not using a tent). When condom manufacturers publish their efficacy data, what they’re saying is that if 100 couples use condoms for one year, only 10 of them will become pregnant that year. (That is, if you’re regularly sleeping outside and using this tent, there’s only a 10% chance you’ll get wet). This does NOT mean that condoms are 90% effective for every act of intercourse, nor does it matter whether or not it’s actually “raining” on any given night. It just means that you are much less likley to get wet/pregnant (8.5 times less likely) if you use condoms for a year than if you use nothing. The condom isn’t getting unfair credit for anything, since it’s understood that some of those women would not have gotten pregnant anyway.
You’re thinking about efficacy in terms of actual “protection” per sexual act. Unfortunately, there’s no way to evaluate or compare that on a population basis, because a) it would be near impossible to determine which particular act of intercourse resulted in pregnancy, and b) the efficacy of natural methods depends not only on the user’s decision to abstain but on the user’s ability to know when to abstain. So, in other words, we can’t evaluate a condom’s efficacy during the fertile period to abstinence during the fertile period; we have to compare the condom user’s success using condoms over some period of time with the NFP user’s success using NFP over the same period of time.
For the record, I’m a huge NFP proponent, and the published literature
does show that NFP is as effective as hormonal contraception (and more effective than condoms).
noclevername:
However I beg to differ that it is more reliable than contraception in preventing pregnancy from a scientific stand point. Can you please please point me to the studies that show this? In my research I have not found any studies that were not funded by a Catholic organization to show this to be true. The only ones I have found were funded by Catholic funds.
Noclevername, If you have access to pubmed, search for and read through the many studies published by either Arevelo (from the Institute for Reproductive Health) or Stanford (who happens to be Mormon). To be fair, though, one really shouldn’t evaluate a study based on the religious affiliation of the primary investigator. Read the literature yourself (even those funded by Catholic sources) and evaluate the research based on the study design and data analysis. I think you’ll be suprised to find that there exists a plethora of objective scientific research which does in fact evidence natural family planning’s high efficacy rate.
God bless.
Ok…took me a while to see the correlation.
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