Published online by Cambridge University Press: 09 December 2014
Survival analysis – specifically the actuarial life-table method and the Cox Proportional Hazards model – was used to assess Bronfenbrenner's bio-ecological model with regards to the onset of sexual intercourse in a random sample of 1697 grade 9 and grade 11 pupils in the North West Province of South Africa. Data were collected in July and August 2007. Of the contextual factors examined, only academic performance and community disorganization were found to be statistically significantly associated with age at first sexual intercourse amongst girls. High academic performance by girls is positively associated with age at first sexual intercourse, while girls who live in disorganized communities initiate sexual intercourse earlier than their counterparts in other communities. Age is negatively associated with the timing of first sexual debut among both girls and boys. Males initiate sexual intercourse earlier than females, while youths with at least one sexual partner are much more likely to initiate sexual intercourse earlier than those without sexual partners.