"At present there does not exist any strong evidence that any abstinence program delays the initiation of sex, hastens the return to abstinence or reduces the number of sexual partners" among teenagers, the study concluded.
The study found that while abstinence-only efforts appear to have little positive impact, more comprehensive sex education programs were having "positive outcomes" including teenagers "delaying the initiation of sex, reducing the frequency of sex, reducing the number of sexual partners and increasing condom or contraceptive use."
"Two-thirds of the 48 comprehensive programs that supported both abstinence and the use of condoms and contraceptives for sexually active teens had positive behavior effect," said the report.
Researcher Doug Kirby reviewed the scientific evaluations of 115 sex ed programs of both the abstinence-only and comprehensive (addressing both abstinence and contraceptives use) variety.
Two-thirds of the comprehensive sex ed programs showed a positive effect on teen sexual behavior, either delaying the initiation of sex or increasing the use of contraceptives, or both.
Debunking the myth that such programs encourage teens to become sexually active, there is no evidence that any of the programs hastened the initiation of sex or increased the frequency of it. Even making condoms available at school clinics didn't make teenagers more likely to have sex.
The best programs send clear and consistent messages about sex and contraceptive use, Kirby said. They talk explicitly about sex and contraceptives, identify specific situations that might lead to unwanted or unprotected sex and involve practicing saying no to sex or insisting on contraceptive use.
Regarding abstinence-only programs, Kirby found that very few of these programs that receive millions in federal dollars have been subject to a rigorous scientific evaluation of their effectiveness. Of those that have, there's no strong evidence that the programs delay the initiation of sex, lead sexually active teens to return to abstinence or reduce a teen's number of sexual partners.
Kirby said he couldn't say all abstinence-only programs don't work because of the scarcity of studies. He said, however, that those studied and found to have no positive impact were chosen for evaluation because they were viewed as the most promising abstinence-only programs.
[She also points out:] Despite the lack of evidence for it, the federal government has cold-shouldered comprehensive sex ed and primarily funded abstinence-only sex ed since 1996. It is spending $176 million on such programs in fiscal 2007 and plans to spend $204 million in fiscal 2008.
Since 1996, taxpayers have paid $1.5 billion for abstinence-only programs when you add in the matching dollars states are required to put up to get the federal funding, Boonstra [of the Guttmacher Institute] said.