Differential effects of socio-demographic factors on maternal haemoglobin concentration in three sub-Saharan African Countries

Abstract

Objective: To investigate the effects of socio-demographic factors on maternal haemoglobin (Hb) at different points of the conditional distribution of Hb concentration. Methods: We analysed the Demographic and Health Surveys data from Ghana, Democratic Republic of the Congo (DRC) and Mozambique, using Hb concentration of women aged 15-49 years as an outcome of interest. We utilise quantile regression to estimate the effects of the putative socio-demographic factors across specific points of the maternal Hb concentration. Results: We observed crucial differences in the effects of socio-demographic factors along the conditional distribution of Hb concentration. In Ghana, years of schooling had a positive effect on Hb concentration of mothers in the 5th and 10th quantiles. A year increase in schooling was associated with a unit increase in Hb concentration across all quantiles in Mozambique, with the largest effect at the lowest quantile. In contrast, a year increase in maternal education was associated with a unit decrease in Hb concentration of mothers in the three upper quantiles in DRC. Maternal body mass index had a positive effect on Hb of mothers in the 5th, 10th, 50th and 90th, and 5th to 50th quantiles in Ghana and Mozambique, respectively. Breastfeeding had a significant positive effect on maternal Hb concentration across all countries, with the largest effect occurring at the lower quantiles. All the household wealth indices had positive effects on Hb concentration across quantiles in Mozambique, with the largest effect among mothers in the upper quantiles. However, in Ghana, living in a poor wealth index was inversely related to Hb concentration of mothers in the 5th and 10th quantiles. Conclusions: Our results showed that the effects of socio-demographic factors on maternal Hb concentration vary along its distribution. Interventions to address maternal anaemia should take these variations into account to identify the most vulnerable groups. Keywords: Haemoglobin concentration, socio-demographics, Africa, quantile regression