Variables sociodemográficas y conductas de riesgo en la infección por el VIH y las enfermedades de transmisión sexual en adolescentes: Espa？a, 2007

background: the development of hiv and std prevention programs needs information about sexual behaviour. the aim of this study is to analyze whether there were differences in hiv/std risk behaviours according to type of high school (public/private), gender and age in adolescents. methods: a representative sample of 4.456 adolescents participated. to select the participants, a stratified random sampling considering spanish regions and type of high school was used. it is a cross-sectional survey study. results: the percentage of adolescents that did not use condoms at first sexual intercourse was higher in private than in public high schools (χ2 (1)=5,06; p=0,02). adolescents who were between 17 and 18 years old had the highest percentage of non condom use at last sexual intercourse (χ2 (2)= 6,90; p=0,03). a higher percentage of males than females had a casual partner at last sexual intercourse (χ2 (1)=127,79; p=0,00). a higher number of adolescents of private high schools than adolescents of public high schools had used drugs at last sexual intercourse (χ2 (1)=5,72; p=0,02), as well as males compared to females (χ2 (1)=36,37; p=0,00). conclusions: differences in hiv risk behaviours according to sociodemographic variables are shown. therefore, taking into account sociodemographic factors in sexual education programs focused on adolescents seems to be necessary.