Freq 1 7 2 10 15 22 51 39 34 23 11 980 % 0.1 0.6 0.2 0.8 1.3 1.8 4.3 3.3 2.8 1.9 0.9 82.0 Female Freq 0 1 0 7 16 23 33 48 38 19 9 681 % 0.0 0.1 0.0 0.8 1.8 2.6 3.8 5.5 4.3 2.2 1.0 77.8 Freq 1 8 2 17 31 45 84 87 72 42 20 1661 % 0 0.4 0.1 0.8 1.5 2.2 4.1 4.2 3.5 2.0 1.0 80.2 8 10 11 12 13 14 15 16 17 18 19 Never Total 1195 100.0 875 100.0 2070 100.0 Females A higher proportion of female adolescents who were liter- ate in English language were sexually abstinent (85.3%) compared to non-literate peers (74.1%) (p < 0.001) (Table 4b). Females who attached high level of impor- tance to religion had statistically lower prevalence of sex- ual intercourse compared to others (79.2% vs. 68.5%) (p = 0.019). Girls with secondary school/higher education were significantly more likely to have initiated sex com- pared to non-educated girls (p < 0.001). However, those with primary school education were more likely to have remained sexually abstinent compared to those with sec- ondary school/higher level of education (p = 0.001). Not surprisingly, personal attitudes in favour of delay of sexual debut were also significantly associated with less sexual engagement (p < 0.001). Also, there was a higher likeli- hood that females who reported having been sexually active came from the South compared with the North of Nigeria (p < 0.001). Economic status was not a significant predictor of sexual initiation. Additionally, the sexually experienced group had signifi- cantly higher scores on the FP access (p = 0.014), FP atti- tudes (p < 0.001), condom norm (p < 0.001), condom efficacy (p < 0.001), condom access (p < 0.001), HIV pre- vention knowledge (p = 0.019) and gender attitude (p < 0.001) scales. Comparison of females who initiated intercourse before and after 16 years of age showed significant differences only with regard to the following: importance attached to religion (p = 0.035); radio exposure (p = 0.008); televi- sion exposure (p = 0.008); secondary school/higher edu- cation versus no formal education (p = 0.039) and BMC Public Health 2008, 8:136 http://www.biomedcentral.com/1471-2458/8/136 Table 3: Distribution of respondents by age of sexual debut Age (years) Male Total primary school (p = 0.024) groups; and, mean score on condom access scale (p = 0.039). Multivariate analyses Of the four selected demographic and community factors – education, age, economic status, urban-rural location, and region – that were incorporated into the first model, only region was significantly associated with adolescent sexual initiation among both males and females. Addi- tionally, educational attainment and age were also signif- icantly associated with sexual initiation among the males (Table 5). As the Cox proportionate hazards model incorporating demographic, community and psychosocial factors shows in Table 6, factors associated with early sexual debut among both males and females were more positive atti- tudes 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 family planning attitudes (males: HR = 1.19, 95% CI = 1.09–1.31; females: HR = 1.18, 95% CI = 1.07–1.30). Conversely, adolescents who favoured delay in sexual debut were about two and half times less likely to initiate sexual intercourse compared with their peers (males: HR = 0.36, 95% CI = 0.25–0.52; females: HR = 0.38, 95% CI = 0.25–0.57). In addition, females who attached more importance to the value of religion were significantly less likely to start sex during adolescence (HR = 0.59, 95% CI = 0.37–0.94) while those that had more positive gender-related dispo- sition, which reflects personal disposition to females' social status and freedom from gender-related violence, were found to have a slightly but statistically significantly increased risk of sexual initiation (HR = 1.13, 95% CI = 1.04–1.23). Among males, the use of alcohol was found to be significantly associated with sexual initiation during adolescence (p < 0.001): those who reported drinking were about twice as likely to report having had sexual intercourse (HR = 1.90, 95% CI = 1.38–2.62). Perceived higher access to condom was also significantly associated with sexual debut among never-married male adolescents (HR = 1.42, 95% CI = 1.14–1.76) (Table 6). Discussion This study had examined the demographic, psychosocial and community factors associated with adolescent sexual initiation using nationally representative sample of Nige- rian adolescents. While a number of studies have been reported on adolescent sexual behaviour in Nigeria, most were small-scale studies that disallow national generalisa- tions. Overall, 18.0% of male and 22.2% of female never-mar- ried adolescents (15–19 years) reported being sexually Page 7 of 14 (page number not for citation purposes)