In 2007 the National Campaign to Prevent Teen and Unplanned Pregnancy issued a report on New Research that Identifies Effictive Teen Sex Education Programs and Other Interventions.
The report, conducted by Dr. Douglas Kirby, PhD, evaluates 115 programs. Two thirds of the programs examined focus on abstinence and contraception and their positive effect on teen behavior.
The report also includes results in regards to access to contraception, condoms and whether educational programs that include parents and teens have any affect on whether teens engage in sexual activity.
You can view the summary of the report here.
Or the full report here.