Compliance and other issues in contraception.

About 5% of women in the United States (approximately three million) are not using contraception despite being at risk of unintended pregnancy. Teenagers have the highest rate of unintended pregnancy. Women 40 years and older most frequently terminate unintended pregnancy. Multiple theories and models, including the health belief model, the health decision model, the Prochaska change model, and the conviction-confidence model, have been developed to address choices and change in health behavior. Despite this information, current data on contraceptive compliance show considerable need for improvement. Side effects and patients' beliefs and preferences appear to influence strongly whether a method will be used appropriately. Systems improvements that address issues such as access and enhancement of provider-patient interaction appear to be areas of potential opportunity. Despite continued need for improvement, there is a paucity of information testing new approaches to improve contraceptive compliance.