Non funzionano

Nicholas Bakalar, «Adolescence: Abstinence-Only Programs Not Found to Prevent H.I.V.», New York Times, 14 agosto 2007:

Abstinence-only programs for H.I.V. prevention do not work, according to a review of randomized, controlled trials. The analysis, published in the August 4 issue of The British Medical Journal, covered 13 studies involving more than 15,000 young Americans.
Most of the programs were based in schools and directed at children in grades five through eight. One was intended for adults ages 18 to 21. There were various control groups, including some in modified programs and in some cases in no program at all. Compared with those control groups, abstinence-only programs had no significant effect in either decreasing or increasing sexual risk behavior.
Seven of the trials tracked sexually transmitted infections, finding no significant short- or long-term benefit to abstinence-only programs. None of the programs made any significant difference in preventing pregnancy, reducing unprotected sex, or delaying sexual initiation.
“We hope our review encourages a closer look at the empirical research regarding H.I.V. prevention programs,” said Kristen Underhill, the lead author and a research officer at the University of Oxford. “It appears that this evidence base is frequently neglected in debates over abstinence-based prevention.”