Education achievements and goiter size ten years after iodized salt consuming

Background: approximately 2.2 billion (2200 million) of the world population are living in the area with iodine deficiency (id),most of them in the developing countries. in iran about 2 million are exposed to iodine deficiency. most of the complications of id are not curable,especially brain damage. on the other hand,adding iodine to daily salt is a suitable program for decreasing iodine deficiency. this has been the main aim of idd national committee since 1986. this study is a before-after preventive trial,and was conducted to determine the effect of iodized salt in preventing the disorders of iodine deficiency. methods: this study was a preventive field trial in 2 stages before and after prevention. since 1995,iodized salt has been distributed in tabas in yazd province. sample of 2,150 students aged 6-18 years were chosen by stratified cluster random sampling method from 24 schools,12 schools from rural and 12 from urban areas. goiter frequency and educational status were determined using who criteria and mean scored,respectively. results: prevalence of goiter has decreased from 34 to 25 percent after 10 years (p < 0.001). the prevalence in urban areas has decreased from 35.8 to 23.5 percent and in rural from 35.6 to 28.5 percent (p = 0.02). prevalence of goiter has changed from 32.8 to 20 percent and from 39.5 to 31.5 in boys and girls,respectively (p < 0.001). there was a statistically significant relation between educational status and goiter frequency before and after prevention (p = 0.01). there was also a statistically significant relation between educational status in 2 stages,before and after intervention (p < 0.001). conclusions: although,there are some confounding variables,such as: educational resources development,improved educational methods,and enhanced family emphasis on extracurricular education,increased frequency of students in higher education after intervention shows the iodine effects on mental function.