Period-cohort effects models for age at first sex in Namibia

Lillian Pazvakawambwa, University of Namibia
Lawrence Kazembe, University of Namibia
Nelago Indongo, University of Namibia

Early sexual debut is often associated with a number of social challenges. However, the hazard and risk factors of changing pattern of age at first sex have not been fully explained. This paper investigated the period-cohort effects by fitting flexible time-to-event models of sexual debut using retrospective cross-sectional data of the 2000 and 2006-7 Namibian Health and Demographic Survey, to establish individual and structural effects, and simultaneously investigated spatial frailty effects, non-linear effects of age, cohort and period on the timing of sexual debut among women. The hazard of sexual debut reduced as the woman’s year of birth increased suggesting a generational effect. The North Eastern parts of Namibia were associated with a higher risk of early sexual debut compared to all other regions. Intervention strategies should be multifaceted and involve not only schools and communities but individual family units as they have a bigger role to play in this regard.