Goiter and other iodine deficiency disorders: A systematic review of epidemiological studies to deconstruct the complex web

A systematic review of the available literature on goiter and other iodine deficiency disorders (IDDs) was carried out with the aim of analyzing available evidence and providing inputs to the policy makers and program formulators regarding the entire issue. The findings point to major issues such as the following: methodological issues in epidemiology of goiter and other iodine deficiency disorders (IDDs); lacunae in causal linkages; inadequate attention to multicausality; flawed assessment of the impact of intervention, i.e., iodized salt; and harmful effects of iodine not given due cognizance. Most of the research to date has been unidirectional and does not provide comprehensive data on all aspects of IDDs. To further compound the issue, many independent researchers, on finding something different from the existing dominant paradigm (iodized salt as panacea for goiter) have tended to ignore these in their final conclusions and recommendations. Thus, evidence from this systematic review demonstrates enough basis to start a debate on the entire issue, recognizing opposing research findings while continuing with the present strategy. This imposes specific problems and necessitates area-specific solutions instead of a universal solution, which apart from being less effective may be harmful in the long run. (C) 2007 IMSS. Published by Elsevier Inc.