Background: The threshold of thyroid-stimulating hormone (TSH) in current screening for congenital hypothyroidism (CH) from the heel prick test is 5 mU/l. This study uses cost-effective analysis to evaluate increasing the threshold to minimize false-positive results and recall rates.
Methods: Cost of screening, diagnosis and treatment, education, and care of mentally retarded patients were gathered from the Ministry of Health State Welfare Organization and Department of Education in Tehran. Screening data were obtained from 34,007 neonates in the Central Health Laboratory of Tehran University of Medical Sciences in 2009. Sensitivity analysis and calculation of confidence interval for incremental costs and effects (gained disability adjusted life years - DALYs) and incremental cost-effectiveness ratios (ICER) were performed by Monte Carlo simulation with Ersatz software.
Results: ICER for screening programs with different TSH cut-off points versus no screening was similar, and approximately -4.5 ± 0.2 thousand US dollars per gained DALY. In the proposed cohort (10,000 neonates), gained DALYs were 316 ± 50 for a cut off point of 5 mU/l, 251 ± 40 for 10 mU/l, 146 ± 23 for 15 mU/l, and 113 ± 18 for a cut-off point of 20 mU/l. Sensitivity analysis showed that the model remained the same when the input parameters were changed.
Conclusion: This study demonstrates that the current threshold of TSH in the national CH screening program in terms of cost-effectiveness is the most appropriate threshold. However, more studies are needed to examine new strategies and methods to reduce recall rates and related consequences such as repeated thyroid testing in neonates.