Spatial patterns and determinants of Anemia in women of reproductive age in Zambia (2018-2024): A multilevel ordinal regression approach

Abstract Background Anemia is a condition characterized by nutritional deficiencies and blood disorders, predominantly affecting children aged 6 to 59 months and women of reproductive age, especially in low and middle-income countries. In Zambia, anemia is a public health problem. This study aims to assess the spatial patterns and determine factors associated with anemia severity in Zambia over six years (2018 to 2024). Method The study included a total of 19,362 WRA from the two waves of the ZDHS, 2018 and 2024. The ZDHS is a periodic national survey that uses multistage sampling. We adopted an analytical cross-sectional design, and the three-level multivariable ordinal logistic regression model was used to identify variables (individual, household, and community level) associated with anemia severity. Global Morans I, Local Morans I, and Getis-Ord Gi* statistics were used to determine the hotspots and spatial patterns, while spatial scan statistics were used to detect primary and secondary clusters and their distribution over the two cycles. Results The prevalence of anemia among women of reproductive age in Zambia was 31.0% (n=3,946) and 30.4% (n=2,015) in 2018 and 2024, respectively. The factors associated with higher odds of anemia severity were HIV status (HIV-positive: AOR=2.63, 95% CI:2.25,3.09), pregnancy (AOR=1.96, 95% CI:1.67,2.31), and rural residency (AOR=1.21, 95% CI:1.08,1.35). While being in a union was protective compared to never being in a union (AOR=0.66, 95% CI:0.57,0.77), not having financial barriers for medical assistance was equally protective. Spatial analysis showed geographic disparities and a non-random distribution of anemia (Global Morans I, 2018: I=0.147, p<0.001; 2024: I=0.130, p<0.001). the Hotspot analysis depicted an expansion of high-risk areas Western in 2018 to the North-Western and Luapula in 2024. Spatial scan analysis identified the south-west region (Western, Southern and North-Western) as the significant primary cluster of anemia consistently for both waves.