Contraceptive use-effectiveness and the American adolescent.

Contraceptive use-effectiveness is significantly shaped by the contraceptors' ages, for pregnancy rates are found to be a function of age. Teenagers are more failure prone than older contracepting women, regardless of method. This higher teenage failure rate can indicate clearly the use-effectiveness of various contraceptive methods. Consequently, both user and method (whether modern or traditional) determine outcome levels of contraceptive use-effectiveness.