What is the effectiveness of different methods of contraception?
The effectiveness of a contraceptive method or measurement is measured by the Pearl Index, which is the number of pregnancies per 100 women after 12 months of use (100 women per year = 1.200 months of application)
A comparative table of the Pearl Index, which is named after Raymond Pearl (1879 - 1940), statistician John Hopkins University in Baltimore, USA.
The lower the number, the more reliable is contraception. So important is the aspect of "practice" of the Pearl Index, as it provides information on the effectiveness of a daily method. Secondly, by its "theoretical" , the Pearl Index describes the effectiveness of this method when applied flawlessly.
The higher the difference between the two values, plus a flawless application is important so that the method is reliable. The smaller the difference, the less the man and woman may commit a faux pas. This index does not take into account the fact that 10 to 15% of all couples can not get pregnant.
Contraceptive Tecnology, 2007, www.contraceptivetechnology.org