Determinants of age at sexual debut and associated risks among South African youths.

The research uses data from a representative national survey to explore the determinants of age at sexual debut among South African youths in the age group 15-24 years. A random sample of 5 708 youths were interviewed and 92% responded to questions on whether or not they had ever had sex and their age at first sex for those who had. The research used survival analyses techniques to combine 'current status data' and 'recall data' for respondents who reported ever having had sex. The females were more likely than the males to report ever having had sex (p≤0.001). The median age at sexual debut was 18 years for both males and females. The hazard ratio pertaining to early sexual debut was 0.81-times less for those in the age group 15-19 as compared to those in the age group 20-24 (p≤0.001). Age, race, geographical location, and level of education were found to be important determinants of age at sexual debut. The 'hazards of sexual debut' (θ=0.112; p≤0.001) varied significantly between geographical areas (rural or urban). Youths with an earlier age of sexual debut were less likely to have used condoms, a behaviour which increases their risk of HIV infection. HIV prevalence was consistently higher among the females than among the males. We recommend that HIV-prevention interventions target community sets rather than only individuals at higher risk of exposure to HIV.