Social vulnerabilities and sexual initiation of 10- to 14-year-old pupils in the city of Rio de Janeiro, Brazil.

This study aimed to estimate the prevalence of sexual initiation of pupils aged 10 to 14 who attended the second year of public and private high school in the IX Administrative Region of the city of Rio de Janeiro, Brazil and to identify the most vulnerable subgroups. The sample consisted of 694 pupils who were selected through cluster-based and stratified sampling by considering school type (public or private) and course type (daytime or evening). Information was collected by means of a structured self-administered questionnaire. The chi-square test (χ2) and 95% confidence intervals were used to assess the heterogeneity of proportions among subgroups. The prevalence of the event was 18.4%; it was higher in boys, in subgroups of greater social vulnerability, among those who hooked up/dated up to 14 years of age, in victims of sexual violence in affective-sexual relationships and in pupils showing health risk behaviors. The high rate of sexual initiation in early adolescence, especially in more vulnerable groups, shows that the situation must be understood and addressed by means of intersectoral public policies that take into account a social context of multiple needs rather than reproductive health alone.