| Abstract: | Many couples will have a long period in which they will practice contraception as a family planning choice. Contraceptive failure rates recently published in the US by Elise Jones and Jacqueline Forest were based on short-term studies. This article extends these short-term failure rates by 3 differing models over a 10-year period. A 95% effective contraceptive method has a monthly 1% chance of failure. Taken over 10 years, this method has a 70% chance of failure. For many couples, 20 years of contraceptive usage is chosen and they may want to be able to choose their contraceptive according to its long-term efficiency. This article focuses on the individual and not on the group because the group's chance of unwanted pregnancy will rapidly decline as the most fecund become pregnant and drop out of subsequent analysis. The individual's risk will not diminish. The 3 models for extending short-term failure rates over 10 years are: 1) annual risk remains constant; 2) annual risk declines by 1/2 over 10 years; and 3) failure rates for various methods reduce to 0 over 10 years. Using the conservative 3 model, the risk of unwanted pregnancy over 10 years is still high for all forms of contraception outside of sterilization (e.g. Pill=27% failure, Condom=52% failure, Diaphragm=56% failure, Rhythm Method=57% failure, Spermicide=76% failure, and IUD=26% failure). There findings have implication for the occurrence of unwanted child bearing and abortion, and the need to look at long term risk is choosing a temporary contraceptive method. |
