Withdrawal is less effective for preventing pregnancy than other contraceptive methods and offers no protection against sexually transmitted infections including HIV. Little is known from a national perspective about adolescents who primarily use withdrawal. This study describes the prevalence of withdrawal as their primary method of pregnancy prevention at last sexual intercourse among sexually active US high school students and associations with sexual risk and substance use.Data from the 2011 National Youth Risk Behavior Survey were used to estimate sexually active students' most recent contraceptive method. Logistic regressions examined sexual behaviors and substance use, comparing students who used withdrawal to those who used no method, a condom and a highly effective method.Among 4793 currently sexually active students, 10.2

作者：Nicole, Liddon；Emily, O'Malley Olsen；Marion, Carter；Kendra, Hatfield-Timajchy

来源：Contraception 2016 年 93卷 2期