Effectiveness of abstinence-only intervention in middle school teens.

Objectives: To examine effectiveness of abstinence-until-marriage curriculum on knowledge, beliefs, efficacy, intentions, and behavior.

Methods: Nonrandomized control trial involving 2069 middle school students with a 5-month follow-up.

Results: Intervention students reported increases in knowledge and abstinence beliefs, but decreases in intentions to have sex and to use condoms.