Independent and combined effects of maternal smoking and solid fuel on infant and child mortality in sub-Saharan Africa

Abstract

Objective: To estimate the independent and combined risks of infant and child mortality associated with maternal smoking and use of solid fuel in sub-Saharan Africa. Methods: Pooled weighted data on 143 602 under-five children in the most recent demographic and health surveys for 15 sub-Saharan African countries were analysed. The synthetic cohort life table technique and Cox proportional hazard models were employed to investigate the effect of maternal smoking and solid cooking fuel on infant (age 0–11 months) and child (age 12–59 months) mortality. Socio-economic and other confounding variables were included as controls. Results: The distribution of the main explanatory variable in households was as follows: smoking + solid fuel – 4.6%; smoking + non-solid fuel – 0.22%; no smoking + solid fuel – 86.9%; and no smoking + non-solid fuel – 8.2%. The highest infant mortality rate was recorded among children exposed to maternal smoking + solid fuel (72 per 1000 live births); the child mortality rate was estimated to be 54 per 1000 for this group. In full multivariate models, the risk of infant death was 71% higher among those exposed to maternal smoking + solid fuel (HR = 1.71, CI: 1.29–2.28). For ages 12 to 59 months, the risk of death was 99% higher (HR = 1.99, CI: 1.28–3.08). Conclusions: Combined exposures to cigarette smoke and solid fuel increase the risks of infant and child mortality. Mothers of under-five children need to be educated about the danger of smoking while innovative approaches are needed to reduce the mortality risks associated with solid cooking fuel.