Analytical approach:
A decision tree was used to synthesise the effectiveness, outcome, and cost data. The authors reported that a societal perspective was adopted.
Effectiveness data:
The clinical and effectiveness data were derived from published literature. The main effectiveness estimate was the effect of treatment by maternal thyroid replacement on the offspring’s individual development.
Monetary benefit and utility valuations:
The utilities for children with an intelligence quotient (IQ) of less than 70, 70 to 85, or over 85, were derived from published studies.
Measure of benefit:
Quality-adjusted life-years (QALYs) gained were the measure of benefit.
Cost data:
The costs included: screening by a random serum thyroid-stimulating hormone (TSH) test, in the first trimester; maternal treatment, including thyroxine test, counselling sessions with a nurse, TSH tests, thyroxine supplementation, and consultant appointments; and care for children with an IQ of less than 70, or between 70 and 85. The screening costs were from Medicare data and the costs associated with low IQ were from a study that evaluated the costs of neurologic outcomes similar to those expected in children with low IQs. All costs were reported in US dollars ($).
Analysis of uncertainty:
: A series of univariate and bivariate sensitivity analyses was undertaken by varying parameters, such as the probability of children having an IQ lower than 85 after thyroid hormone replacement, the prevalence of disease, and the inclusion of disutility estimates for iatrogenic hyperthyroidism in the mother.