Age at First Marriage and Fertility Decline in Dabat Health and Demographic Surveillance System Site, northwest Ethiopia: Decomposition analysis
Abstract Background: Fertility declines in Ethiopia have been documented since 1990s. Amhara National Regional State has recorded the most noticeable fertility decline. However, specific factors that explain the incipient course of fertility decline in the study area and their relative contributions were not well investigated. Hence, the purpose of this study was to determine the factors that contributed for fertility decline, and to assess the variations in fertility that can be attributed to both changes in characteristics and reproductive behaviors of women aged 15–49 years between 2008 and 2014 in Dabat Demographic and Health Surveillance System Site, Northwest Ethiopia.Methods: Cross sectional censuses were carried out in Dabat Health and Demographic Surveillance System site in 2008 and 2014. Data for 4,775 and 10,807 women with reproductive age in 2008 and 2014 were used for the analysis. Poisson regression model was employed to assess the trends of determinants of fertility, and Multivariate Decomposition technique was applied to evaluate observed changes in fertility using data from two consecutive cross-sectional censuses of Dabat HDSS conducted in 2008 and 2014.Results: The findings indicated that there was a reduction of an average 641 births per 1,000 women of the reproductive age during the year 2014 compared to the year 2008 in the surveillance site (P-value <0.001; 95% CI: -669.5, -582.4). This overall change in fertility during the study period was attributed to both changing characteristics of women (the distribution effect) (78%) (P-value <0.001; 95%CI: -537.65, -462.32), and their reproductive behavior (the effect shown by regression coefficients of the variables on the outcome) (22%) (P-value <0.001; 95% CI: -214.56 to -67.368). The drivers of the recent fertility decline during the study period were the shift observed in the age at first marriage, the change in the proportion of currently married women, the shift in women’s birth to later age and the change in women's educational status.Conclusion: This study indicated that the overall reduction in fertility was attributed to both changing characteristics of women and their reproductive behavior. The major contributors to the changes in fertility were the postponing of women’s first marriage to later age and the change in the proportion of currently married women over the study period. Encouraging women to complete at least secondary education are important to increase the age at first marriage and birth which intern accelerate the current fertility transition.