Hotspots of un-iodized salt availability among Ethiopian households, evidence from the national survey data

**Background:** Iodine deficiency is a major preventable cause of mental impairment globally, and universal salt iodization is a key public health strategy. Ethiopia is the third country with the highest rate of non-iodized salt availability among sub-Saharan African countries. Despite national efforts, more than one-tenth of Ethiopian households still use un-iodized salt. This study aimed to identify geographic hotspots and associated factors of un-iodized salt availability using nationally representative data.

**Methods:** The authors conducted an in-depth secondary analysis of the Ethiopian Demographic and Health Survey (EDHS) 2016, a nationwide cross-sectional study conducted from January to June 2016. A total of 15,567 households from 645 enumeration areas were included in the final analysis. Data were cleaned and weighted using Stata version 16. The weighted prevalence of un-iodized salt was computed and prepared for spatial analysis. Global spatial autocorrelation was assessed using Moran's I, hotspot analysis was performed using Getis-Ord Gi* statistics, and spatial interpolation was conducted using empirical Bayesian interpolation in ArcGIS 10.3. Binary logistic regression was used to identify factors associated with un-iodized salt utilization. Model goodness of fit was tested with the Hosmer and Lemeshow test (P = 0.96). Adjusted odds ratios (AOR) with 95% confidence intervals (CI) were reported.

**Key Results:** The overall magnitude of un-iodized salt availability was 14.19% (95% CI: 13.65, 14.75). Regional variation was substantial: Somali region had the highest proportion (37.50%), followed by Afar (25.76%), while Benishangul Gumuz had the lowest (5.81%). Spatial analysis revealed significant geographic clustering (global Moran's I = 0.31, P < 0.001, Z-score = 18.90). Hotspot clusters (high prevalence of un-iodized salt) were identified in zones of Somali, Afar, and SNNPR regions. The prediction map using empirical Bayesian interpolation confirmed high prevalence in most of Afar and Somali regions. In the multivariable logistic regression, wealth index was significantly associated with un-iodized salt availability: compared to the poorest households, poorer (AOR = 0.55, 95% CI: 0.48, 0.64), middle (AOR = 0.51, 95% CI: 0.44, 0.60), richer (AOR = 0.55, 95% CI: 0.47, 0.64), and richest (AOR = 0.61, 95% CI: 0.50, 0.75) households had significantly lower odds of having un-iodized salt. Education of the household head was also protective: secondary education (AOR = 0.72, 95% CI: 0.60, 0.87) and higher education (AOR = 0.54, 95% CI: 0.43, 0.67) reduced the odds compared to no education. Living at high altitude (≥2200 meters above sea level) increased the odds of un-iodized salt availability (AOR = 1.16, 95% CI: 1.05, 1.29).

**Clinical Implications:** More than one in ten Ethiopian households use un-iodized salt, placing a substantial population at risk for iodine deficiency disorders, including goiter and cognitive impairment. The identification of hotspots in Afar, Somali, and Benishangul Gumuz regions suggests that local salt production from un-iodized sources (e.g., Afdera and Asale lakes) and challenges in iodization and transportation contribute to the problem. Interventions should prioritize these hotspot regions, improve household wealth and education, and address the logistical barriers to iodized salt distribution in high-altitude areas. The study is limited by its cross-sectional design and lack of data on behavioral factors and knowledge about iodized salt.