Regional and Sex Differences in the Prevalence and Correlates of Early Sexual Initiation Among Adolescents Aged 12-15 Years in 50 Countries.

PURPOSE

This study aimed to investigate the regional and sex differences in the prevalence of early sexual initiation and its correlates among school-going adolescents in 50 countries.

METHODS

We used data from the Global School-based Health Survey from 50 countries in 2009-2015 for 124,091 adolescents (53.5% girls) aged 12-15 years. Using meta-analysis with random effects, we estimated the prevalence of early sexual initiation (i.e., having first sexual intercourse at ≤14 years) by sex, region, and country income classification. Multilevel mixed-effect logistic regressions including a random intercept for countries were used to investigate the correlates of early sexual initiation.

RESULTS

Overall, 14.2% (95% confidence interval: 12.1-16.2) of adolescents aged 12-15 years had early sexual initiation, with boys reporting much higher than girls (19.7%, 16.9-22.5 vs. 8.9%, 7.6-10.3). The prevalence of early sexual initiation was the highest in the region of the Americas (18.4%, 15.2-21.5) and the lowest in the South-east Asia region (5.3%, 2.6-8.0). Adolescents from high-income and lower middle-income countries had the highest (19.5%, 13.5-25.5) and the lowest (7.3%, 5.5-9.0) prevalence, respectively. Older age, anxiety, loneliness, suicidal ideation, being bullied, physical fight, school truancy, smoking, drinking alcohol, illicit drug use, physical activity, and being overweight were associated with higher odds of early sexual initiation, whereas female sex, parental monitoring, and peer support were protective. There was little or no evidence of heterogeneity by sex and across regions for these associations.

CONCLUSIONS

Substantial differences in the prevalence are observed by sex and across regions for early sexual initiation among adolescents, whereas its correlates remain relatively similar when examined separately by these characteristics.