Utilisation of adequately iodized salt and influencing factors among Malawian households with children under five years old: analysis of data from the multiple indicator cluster survey 6

Abstract Background Iodine is an essential micronutrient required to produce thyroid hormones, which regulate growth, development and metabolism. Insufficient dietary iodine can lead to iodine deficiency disorders (IDD), particularly affecting cognitive development in young children. The WHO recommends fortifying salt with iodine and targeting at least 90% of household consumption of adequately iodized salt (≥ 15 ppm) to prevent IDD. Methods We analyzed data from the 2020–2021 Multiple Indicator Cluster Survey to estimate the prevalence of adequately iodized salt use in households with children under five and to identify associated factors. Mixed-effects univariate and multivariable logistic regression were used, with random intercepts for households nested in district strata. Results Among 11,406 households, 62% (95% CI 61–63) used adequately iodized salt. Among the remainder, 31% (95% CI 30–32) used salt that contained some iodine (< 15 ppm iodine), and 7% (95% CI 7–8) used non-iodized salt. Higher education was positively associated with utilization: lower secondary education aOR 1.29 (1.07–1.54), p-value 0.005; upper secondary education aOR 1.35 (1.13–1.61), p-value 0.001; and tertiary aOR 1.63 (1.17–2.30), p-value 0.004. Higher household wealth also increased utilization (aOR 1.42 (1.33–1.54), p-value < 0.001). Conversely, rural residence and living in the Southern region were associated with reduced odds of adequately iodized salt use. Conclusion Although utilization of iodized salt in Malawi has increased from previous surveys, it remains below the WHO target of 90%, placing households, especially in rural and high-poverty areas, at risk of IDD. Interventions to improve access, affordability and awareness of adequately iodized salt are urgently needed to accelerate progress toward universal salt iodization and reduce the burden of iodine deficiency, particularly among young children.