RT Journal Article SR Electronic T1 Review: primary prevention strategies do not improve contraceptive use or reduce pregnancies in adolescents JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 18 OP 18 DO 10.1136/ebm.8.1.18 VO 8 IS 1 YR 2003 UL http://ebm.bmj.com/content/8/1/18.abstract AB