Iodine levels in household and market salt, and associated knowledge, attitudes, and practices in Ethiopia: a nationwide cross-sectional study

BACKGROUND: Salt iodization is a key strategy in the global effort to eliminate iodine deficiency disorders. In Ethiopia, iodized salt coverage has fluctuated over the years, potentially linked to consumers' knowledge, attitudes, and practices (KAP). This study aimed to evaluate iodine levels in salt samples from households and markets and to assess KAP related to iodized salt consumption. METHODS: A community-based cross-sectional study was conducted, collecting 1862 salt samples (931 from households and 931 from markets) from nine regions and two city administrations in Ethiopia. KAP data were collected via a questionnaire-based survey, and iodine concentration in the salt samples was determined using iodometric titration. RESULTS: The study found that 88.1% of households consumed adequately iodized salt (≥ 15 ppm), with a mean iodine concentration of 43.9 ppm (95% CI: 42.4, 45.6). Coverage below the recommended level (11.3%) showed significant regional variation, with the lowest coverage observed in Tigray and Afar. Market coverage was slightly higher at 89.1% with a mean iodine concentration of 48.9 ppm (95% CI: 46.1, 49.9). Regarding KAP, 53.1% of women had heard of iodized salt, but awareness of iodine loss from improper storage and handling was low; 56.9% of households reported adding salt after cooking. In multivariable analysis, requesting iodized salt during purchase (AOR = 2.45; 95% CI: 1.82, 3.31), storing salt in a container with a lid (AOR = 1.92; 95% CI: 1.45, 2.54), adding salt after cooking (AOR = 1.68; 95% CI: 1.21, 2.33), and having heard of iodized salt (AOR = 1.34; 95% CI: 1.02, 1.76) were independently associated with having adequately iodized household salt. CONCLUSION: Ethiopia has high iodized salt coverage at household (88.1%) and market (89.1%) levels, but consumer knowledge and handling practices remain insufficient, risking iodine losses before consumption. The lowest household coverage and iodine concentrations were observed in Tigray and Afar. Public health actions should prioritize region-specific behavior change communication (e.g., low-coverage regions) focused on purchasing iodized salt, airtight storage, and appropriate use during cooking, alongside strengthened quality control in the supply chain.