Predictors of early sexual initiation among a nationally representative sample of Nigerian adolescents

Background. Early sexual debut among adolescents is associated with considerable negative heath and development outcomes. An understanding of the determinants or predictors of the timing of sexual debut is important for effective intervention, but very few studies to date have addressed this issue in the Nigerian context. The aim of the present study is to examine predictors of adolescent sexual initiation among a nationally representative sample of adolescents in Nigeria. Methods. Interviewer-collected data of 2,070 never-married adolescents aged 15-19 years were analysed to determine association between age of sexual debut and demographic, psychosocial and community factors. Using Cox proportional hazards regression multivariate analysis was carried out with two different models - one with and the other without psychosocial factors. Hazard ratio (HR) and 95% confidence interval (CI) were calculated separately for males and females. Results. A fifth of respondents (18% males; 22% females) were sexually experienced. In the South 24.3% males and 28.7% females had initiated sex compared to 12.1% of males and 13.1% females in the North (p < 0.001). In the first model, only region was significantly associated with adolescent sexual initiation among both males and females; however, educational attainment and age were also significant among males. In the second (psychosocial) model factors associated with adolescent sexual debut for both genders included more positive attitudes regarding condom efficacy (males: HR = 1.28, 95% CI = 1.07-1.53; females: HR = 1.24, 95% CI = 1.05-1.46) and more positive attitudes to family planning use (males: HR = 1.19, 95% CI = 1.09-1.31; females: HR = 1.18, 95% CI = 1.07-1.30). A greater perception of condom access (HR = 1.42, 95% CI = 1.14-1.76) and alcohol use (HR = 1.90, 95% CI = 1.38-2.62) among males and positive gender-related attitudes (HR = 1.13, 95% CI = 1.04-1.23) among females were also associated with increased likelihood of adolescent sexual initiation. Conversely, personal attitudes in favour of delayed sexual debut were associated with lower sexual debut among both males (males: HR = 0.36, 95% CI = 0.25-0.52) and females (HR = 0.38, 95% CI = 0.25-0.57). Higher level of religiosity was associated with lower sexual debut rates only among females (HR = 0.59, 95% CI = 0.37-0.94). Conclusion. Given the increased risk for a number of sexually transmitted health problems, understanding the factors that are associated with premarital sexual debut will assist programmes in developing more effective risk prevention interventions.