Spatial disparities of antenatal care utilization among pregnant women in sub-Saharan Africa-Bayesian geo-additive modelling approach

Abstract

Background: Antenatal care (ANC) is critical for ensuring healthy pregnancies and positive birth outcomes. Despite its importance, significant disparities in ANC access and utilization exist across sub-Saharan Africa (SSA), influenced by various socioeconomic, geographical, and systemic factors. This study aimed to analyze the spatial disparities in the proportion of recommended ANC utilization and its associated risk factors among pregnant women in 34 sub-Saharan African countries.

Method: This study utilized the most recent Demographic and Health Survey (DHS) data from 34 countries across the SSA region. To assess the spatial disparities and their associated risk factors of ANC utilization, a geo-additive model via the Integrated Nested Laplace Approximation (INLA) was adopted.

Result: The overall prevalence of recommended ANC utilization in SSA was 22.15%, with a significant difference between countries, ranging from 0.27% in Rwanda to 76.28% in Zimbabwe. Both Moran's I and Geary's C tests, with different neighborhood structures, evidenced the existence of spatial autocorrelation of ANC utilization among women in SSA countries. A Bayesian geo-additive model with Besag-York-Mollié (BYM) mixed effect was found to be the best model to assess the spatial dependencies and the non-linear effects of the factors on ANC utilization among women of reproductive age. The study showed that the existence of spatial disparities in ANC utilization and media exposure, as well as the mother's work status, partner's working status, age of mother, age at first cohabitation, and place of delivery, has a significant effect on ANC utilization.

Conclusion: The overall coverage of recommended ANC in SSA countries falls short of the global minimum recommended ANC utilization. The lower coverage and inequality of ANC utilizations are influenced by underutilization of healthcare services, economic status, women's education coverage, poor/absence of transportation facilities, and media exposure related to healthy reproduction. Empowering women through different media outlets, strengthening their economic power, easy access to health facilities, and decision-making power increases maternal healthcare service utilization.

Keywords: INLA; antenatal care contacts; geo-additive; spatial disparities; sub-Saharan Africa.

Figure 1

Lists of sub-Saharan African countries considered in this study.

Figure 2

Diagrammatic representation of outcome variables and the respective factors.

Figure 3

Proportion of minimum recommended ANC utilizations for women of reproductive age across SSA countries.

Figure 4

Proportion of minimum recommended ANC utilization for pregnant women of reproductive age across the SSA region.

Figure 5

Forest plot of proportion of recommended ANC utilization in SSA countries, and sub-region, and survey year aggregates.

Figure 6

Spatial maps of observed and fitted antenatal care utilization using three different models (linear model, additive with fixed effect, and additive with mixed effect models; with the corresponding residuals).

Figure 7

Maps of observed and posterior estimated of proportion antenatal care visits using three different competing Bayesian additive models (without random effect, random effect (with IID), random effect (with BYM) and the corresponding residuals).

Figure 8

Plots of Posterior mean of non-linear effect of risk factors; (A) Women working status, (B) Media Exposure, (C) Partner’s Working status, (D) Proportion of poor HH, (E) Total Number of Children, (F) Mother’s current age, (G) Sex of household head, (H) Health Facility, (I) Contraceptive use, respectively.

Figure 9

Plots of probability integral transform (PIT) and conditional predictive ordinate (CPO) for the measure of goodness of the Besag-York-Mollié model fit.