Social context of contraceptive use transition among sexually active women in Zambia (1992-2018): A decomposition analysis.

Background: Contraception is an important public health initiative for addressing maternal health outcomes associated with unplanned pregnancies, unsafe abortions and maternal deaths. Although contraceptive use has been on the rise globally, the observed increases in sub-Saharan Africa (SSA) are sub-optimal and vary among countries. In Zambia, drivers of contraceptive use transition are not well documented. Thus, this study examined the drivers of contraceptive use change among sexually active women in Zambia between 1992 and 2018.

Methods: Data came from the six Zambia Demographic and Health Surveys conducted between 1992 and 2018. A sample of 44,762 fecund sexually active women aged 15-49 years was analysed using multivariable Blinder Oaxaca decomposition regression analysis. Analysis took into account the complex survey design. Results were presented using adjusted coefficients, their 95% confidence intervals, and percentages.

Results: The prevalence of contraceptive use among sexually active women increased significantly by 30.8 percentage points from 14.2% (95% CI: 12.8, 15.6) to 45.0% (95% CI: 43.6, 46.4) during the period 1992 to 2018. The major share of the increase happened during the period 1992-1996 (10.2%) while the least increase occurred between 2013 and 2018 (0.2%). Overall, about 15% of the increase in the prevalence of contraceptive use was attributable to changes in the compositional characteristics of women. On the other hand, 85% of the increase was due to change in contraceptive behaviour of sexually active women. Changes in women's compositional characteristics such as secondary education (5.84%), fertility preference (5.63%), number of living children (3.30%) and experience of child mortality (7.68%) were associated with the increase in contraceptive use prevalence.

Conclusion: Change in contraceptive behaviour of sexually active women contributed largely to the observed increase in contraceptive use prevalence in Zambia. Increase in the proportion of women attaining secondary education, decrease in the percentage of women who want large families and improvement in child survival were the major compositional factors driving the rise in contraceptive use. The findings imply that increasing investment in education sector and enhancing existing family planning programmes has the potential to further improve contraceptive use prevalence in Zambia.