Regression Analysis to Identify Factors Associated with Household Salt Iodine Content at the Sub-National Level in Bangladesh, India, Ghana and Senegal.

Jacky Knowles,Jonathan Gorstein,Chandrakant Pandav,Kapil Yadav,Greg Garrett,Baitun Nahar,Esi Amoaful,Roland Kupka,Sam Dumble,Ndeye Touré

doi:10.3390/nu10040508

Abstract

Regression analyses of data from stratified, cluster sample, household iodine surveys in Bangladesh, India, Ghana and Senegal were conducted to identify factors associated with household access to adequately iodised salt. For all countries, in single variable analyses, household salt iodine was significantly different (p < 0.05) between strata (geographic areas with representative data, defined by survey design), and significantly higher (p < 0.05) among households: with better living standard scores, where the respondent knew about iodised salt and/or looked for iodised salt at purchase, using salt bought in a sealed package, or using refined grain salt. Other country-level associations were also found. Multiple variable analyses showed a significant association between salt iodine and strata (p < 0.001) in India, Ghana and Senegal and that salt grain type was significantly associated with estimated iodine content in all countries (p < 0.001). Salt iodine relative to the reference (coarse salt) ranged from 1.3 (95% CI 1.2, 1.5) times higher for fine salt in Senegal to 3.6 (95% CI 2.6, 4.9) times higher for washed and 6.5 (95% CI 4.9, 8.8) times higher for refined salt in India. Sub-national data are required to monitor equity of access to adequately iodised salt. Improving household access to refined iodised salt in sealed packaging, would improve iodine intake from household salt in all four countries in this analysis, particularly in areas where there is significant small-scale salt production.

Highlights

Universal salt iodisation (USI) is globally accepted as the most cost-effective public health strategy to prevent iodine deficiency
In single variable regression analyses, salt iodine content was significantly associated with indicators of: location, socio-economic status, knowledge and awareness of iodised salt, and salt supply
Disparities in household access to adequately iodised salt has been a common observation in a number of countries, even after a period of years implementing salt iodisation

Summary

Introduction

Universal salt iodisation (USI) is globally accepted as the most cost-effective public health strategy to prevent iodine deficiency. Despite the global success there is an increasingly apparent inequity in household access to adequately iodised salt within some countries [4,5,6]. A strong evidence base for which determinants are most associated with household salt iodine content, and in which context, is lacking. This gap in sub-national data presents a challenge to the design of strategies to improve equity of access to adequately iodised household salt

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Conclusion