1969-kevany.pdf: “Prophylaxis and Treatment of Endemic Goiter with Iodized Oil in Rural Ecuador and Peru”, John Kevany, Rodrigo Fierro-Benitez, Eduardo A. Pretell, John B. Stanbury (1969-12-01):
Endemic goiter continues to be a substantial health problem in many areas of the world. In some areas the disease is so severe that cretinism and other associated defects are found. In many areas, geographic, economic, and other factors prevent the use of iodized salt as a preventive measure.
A pilot program using iodized poppy seed oil has been instituted in two rural communities in Ecuador and three in Peru. Results after approximately 2 years indicate the feasibility and effectiveness of the programs. There has been a sharp reduction in the incidence of goiter. Cretinism has not yet appeared among the progeny of the population injected with iodized oil, but several instances have appeared in control groups. The use of iodized oil as a public health procedure for the prevention of endemic goiter and its associated defects is an acceptable measure in regions where salt-iodization programs cannot be presently undertaken.
2002-case.pdf: “Economic Status and Health in Childhood: The Origins of the Gradient”, Anne Case, Darren Lubotsky, Christina Paxson (2002-12-01):
The well-known positive association between health and income in adulthood has antecedents in childhood. Not only is children’s health positively related to household income, but the relationship between household income and children’s health becomes more pronounced as children age. Part of the relationship can be explained by the arrival and impact of chronic conditions. Children from lower-income households with chronic conditions have worse health than do those from higher-income households. The adverse health effects of lower income accumulate over children’s lives. Part of the intergenerational transmission of socioeconomic status may work through the impact of parents’ income on children’s health.
I study the impact of salt iodization in Switzerland on graduation rates. The programme, which began in 1922 and continues to this day, was the first wide-reaching nutritional intervention ever to take place. Iodine deficiency in utero causes mental retardation, and correcting the deficiency is expected to increase the productivity of a population by increasing its cognitive ability. The exogenous increase in cognitive ability brought about by the iodization program is also useful in the context of disentangling the effects of innate ability and education on later-life outcomes. I identify the impact of iodization on graduation rates by exploiting pre-existing geographic variation in the prevalence of iodine deficiency, as well as spatial and temporal variation in the introduction of iodized salt across Swiss cantons. By looking at sharp, discontinuous increases in iodized salt circulation I show that the eradication of iodine deficiency in previously deficient areas statistically-significantly increased graduation rates from upper secondary and tertiary education. My results are robust to falsification tests and different measures of iodine deficiency. [Keywords: Cognitive ability, education, human capital, productivity]
2015-monahan.pdf: “Costs and benefits of iodine supplementation for pregnant women in a mildly to moderately iodine-deficient population: a modelling analysis”, Mark Monahan, Kristien Boelaert, Kate Jolly, Shiao Chan, Pelham Barton, Tracy E. Roberts (2015-08-10):
Background: Results from previous studies show that the cognitive ability of offspring might be irreversibly damaged as a result of their mother’s mild iodine deficiency during pregnancy. A reduced intelligence quotient (IQ) score has broad economic and societal cost implications because intelligence affects wellbeing, income, and education outcomes. Although pregnancy and lactation lead to increased iodine needs, no UK recommendations for iodine supplementation have been issued to pregnant women. We aimed to investigate the cost-effectiveness of iodine supplementation versus no supplementation for pregnant women in a mildly to moderately iodine-deficient population for which a population-based iodine supplementation programme—for example, universal salt iodisation—did not exist.
Methods: We systematically searched MEDLINE, Embase, EconLit, and NHS EED for economic studies that linked IQ and income published in all languages until Aug 21, 2014. We took clinical data relating to iodine deficiency in pregnant women and the effect on IQ in their children aged 8–9 years from primary research. A decision tree was developed to compare the treatment strategies of iodine supplementation in tablet form with no iodine supplementation for pregnant women in the UK. Analyses were done from a health service perspective (analysis 1; taking direct health service costs into account) and societal perspective (analysis 2; taking education costs and the value of an IQ point itself into account), and presented in terms of cost (in sterling, relevant to 2013) per IQ point gained in the offspring. We made data-supported assumptions to complete these analyses, but used a conservative approach that limited the benefits of iodine supplementation and overestimated its potential harms.
Findings: Our systematic search identified 1361 published articles, of which eight were assessed to calculate the monetary value of an IQ point. A discounted lifetime value of an additional IQ point based on earnings was estimated to be £3297 (study estimates range from £1319 to £11 967) for the offspring cohort. Iodine supplementation was cost saving from both a health service perspective (saving £199 per pregnant woman [sensitivity analysis range –£42 to £229]) and societal perspective (saving £4476 per pregnant woman [sensitivity analysis range £540 to £4495]), with a net gain of 1·22 IQ points in each analysis. Base case results were robust to sensitivity analyses.
Interpretation: Iodine supplementation for pregnant women in the UK is potentially cost saving. This finding also has implications for the 1·88 billion people in the 32 countries with iodine deficiency worldwide. Valuation of IQ points should consider non-earnings benefits—eg, health benefits associated with a higher IQ not germane to earnings.
2015-politi.pdf: “The effects of the generalized use of iodized salt on occupational patterns in Switzerland”, Dimitra Politi (2015-12-15):
I estimate the long-term impact of the first large-scale nutritional supplementation program, salt iodization, which took place in Switzerland in the 1920s and 1930s. Iodized salt improved the health environment in utero, and it eradicated mental retardation caused by insufficient iodine intake. By exploiting variation in the pre-existing prevalence of iodine deficiency, as well as differences in the timing of the intervention across Swiss cantons, I show that cohorts born in previously highly deficient areas after the introduction of iodized salt were more likely to enter top-tier occupations with higher cognitive demands. As a result, wages of these cohorts were higher, accounting for about 1.9% of annual median earnings, or 2% of Swiss GDP per capita in 1991. [Keywords: Iodine deficiency, cognitive ability, occupational choice, human capital, productivity]