Sexual risk behaviors increasing among adolescents over time: comparison of two cohorts in Spain.

Despite advances in treatment and prevention, HIV/AIDS remains a serious health and social problem. This study's objective is to examine sexual behavior, levels of knowledge, and attitudes toward HIV/AIDS between two cohorts in Spanish adolescents, and to analyze gender differences in these cohorts. Participants were 2132 adolescents between 15 and 18 years of age: 1222 in 2006 (43.2% boys) and 910 in 2012 (54.1% boys). The results indicate lower HIV knowledge and less favorable attitudes about HIV/AIDS in the 2012 cohort. In addition, adolescents from the 2012 cohort had their first sexual intercourse at an earlier age and have more sexual partners than those from the 2006 cohort. Compared to boys, girls engage in fewer risky behaviors, although they did not use condoms with their stable partner; girls tended to use condom less when they were in a stable relationship than boys. This study confirms the insufficiency of prevention campaigns as well as the need to improve the impact from programs that promote healthy sexual habits. Assuming comparability of cohorts, this study suggests increased risk of HIV/AIDS over time.