A survival analysis of the timing of onset of childbearing among young females in Nigeria: are predictors the same across regions?

BACKGROUND: Early childbearing comes at high health costs to girls, the children they bear, their future life chances and the larger society. Nationally representative data suggest variation in onset of childbearing across regions and states of the country. Yet, there is need for strong evidence on how background characteristics explain time to first birth among young females across regions in Nigeria. METHODS: We analysed the 2013 DHS dataset using Kaplan Meier and Cox Regression. The outcome variable is age at onset of childbearing with location (rural/urban), education, religion, wealth index, region and having ever married/cohabited as covariates. Models were computed for national level analysis and the six regions of the country. RESULTS: The effect of marriage/cohabitation on time to first birth is strong and universal across the regions. Ever married girls had higher adjusted hazard ratios for starting childbearing than single girls, ranging from 5.35 in the South South to 44.62 in the North West (p < 0.001 in all models). Education also has significant effect on time to first birth across regions. The significance of state of residence, wealth, and religion varies across regions. CONCLUSION: We conclude that the combinations of factors that explain onset of childbearing vary across regions. Therefore, context specific factors should be considered in program designs aimed at achieving a significant reduction in early childbearing and similar problems in Nigeria.