People consider many factors when deciding which contraceptive method(s), if any, to use. The best contraceptive method is one that is safe and which aligns with the user’s preferences, desires, and values. In choosing a contraceptive method, people generally weigh many factors, such as side effects, safety, ease of use, cost, and other personal or contextual aspects. Contraceptive effectiveness is often a primary consideration, though generally not the only one. Contraceptive effectiveness varies according to many factors, including the intrinsic efficacy of the method, whether the method is easy to use correctly, and user characteristics (age, parity, etc.).
The book Contraceptive Technology is widely known as a definitive clinical reference on contraception and reproductive health. This paper provides a summary of contraceptive effectiveness data drawn from the chapter “Effectiveness, Safety, and Comparative Side Effects” in Contraceptive Technology, 22nd Edition; for a more comprehensive discussion, we strongly encourage readers to refer to the chapter; this manuscript provides a high-level summary whereas the chapter provides additional nuanced details within each method category.