Abstinence and safer sex among adolescents.

To the Editor: The study by Dr Jemmott and colleagues 1 contributes important data to the effort to develop effective interventions that prevent sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV) disease among young people. Although the authors used an ambitious study design and went to substantial lengths to document and validate the self-reported behaviors that were the principal outcome measures , we believe this and other such studies could be strengthened by the use of biomedical markers that identify STDs. The availability of sensitive and specific urine-based testing for some of the most common bacterial STDs (ie, chlamydia and gonorrhea) makes such assessment feasible, even among subjects who do not report sexual activity. As O'Leary et al 2 have noted, " the real outcome of interest in intervention research is morbidity: rates of HIV, of other sexually transmitted infections [STIs] in the population or in a group of individuals and incident HIV/STD at the individual level. " While we agree that since the population studied was so young (mean age, 11.8 years) and sexually inexperienced (only 25.2% reported ever having sexual intercourse), preventing establishment of at-risk behaviors is a critical outcome, we would still encourage the use of biomedical markers in the evaluation. The biomedical assessment of STDs can contribute importantly to the assessment. On one hand, experimental interventions can be associated with differences in self-reported behavior change without differences in rates of STD acquisition being observed. 3 On the other hand, a recent study found that a counseling based approach was associated with only a modest effect in reducing self-reported risk behavior, but had greater impact on the rate of acquired STD. 4 We would like to emphasize that behavioral interventions are not the only primary prevention modality for preventing STDs. The diagnosis and treatment of communicable diseases such as STDs prevent ongoing transmission of disease and constitute both primary and secondary prevention. Screening and treating STDs, particularly as part of broad control programs, is an important primary prevention intervention that is effective in reducing community prevalence of disease and morbidity.