Maternal Serologic Screening to Prevent Congenital Toxoplasmosis: A Decision-Analytic Economic Model

Abstract

ObjectiveTo determine a cost-minimizing option for congenital toxoplasmosis in the United States.Methodology/Principal FindingsA decision-analytic and cost-minimization model was constructed to compare monthly maternal serological screening, prenatal treatment, and post-natal follow-up and treatment according to the current French (Paris) protocol, versus no systematic screening or perinatal treatment. Costs are based on published estimates of lifetime societal costs of developmental disabilities and current diagnostic and treatment costs. Probabilities are based on published results and clinical practice in the United States and France. One- and two-way sensitivity analyses are used to evaluate robustness of results. Universal monthly maternal screening for congenital toxoplasmosis with follow-up and treatment, following the French protocol, is found to be cost-saving, with savings of $620 per child screened. Results are robust to changes in test costs, value of statistical life, seroprevalence in women of childbearing age, fetal loss due to amniocentesis, and to bivariate analysis of test costs and incidence of primary T. gondii infection in pregnancy. Given the parameters in this model and a maternal screening test cost of $12, screening is cost-saving for rates of congenital infection above 1 per 10,000 live births. If universal testing generates economies of scale in diagnostic tools—lowering test costs to about $2 per test—universal screening is cost-saving at rates of congenital infection well below the lowest reported rates in the United States of 1 per 10,000 live births.Conclusion/SignificanceUniversal screening according to the French protocol is cost saving for the US population within broad parameters for costs and probabilities.

Diagnosis, Treatment, and Prevention of Congenital Toxoplasmosis in the United States

“…One cost-effectiveness model was recently developed by Stillwaggon et al 7 to evaluate the implementation of universal antepartum screening after the French protocol of monthly serologic screening during pregnancy (including confirmatory testing at a reference laboratory of any positive results) with antepartum treatment, fetal ultrasonography/ AF PCR assay, and infant follow-up/ treatment. 7 This decision analysis made a number of assumptions, including a cost of $12 per test, an estimated cost of fetal death of over $6 million, and an incidence of acute primary maternal infection during pregnancy of 1 in 1000 (including additional sensitivity analyses).…”

“…7 This decision analysis made a number of assumptions, including a cost of $12 per test, an estimated cost of fetal death of over $6 million, and an incidence of acute primary maternal infection during pregnancy of 1 in 1000 (including additional sensitivity analyses). It also assumed that treatment was highly efficacious and inexpensive.…”

“…7, 96, 131, 222 -226 A study limitation that was acknowledged by Stillwaggon et al 7 Moreover, the following changes in the future may make the universal screening strategy even more costeffective: (1) "point-of-care test" technologies for serologic screening, (2) screening with the use of saliva specimens, and (3) multiplex screening 227 (multiplex IgG/IgM, which already are under evaluation and will soon provide further costsaving alternatives for screening). In addition, screening for >1 congenital disease at the same time will provide further cost savings.…”

“…In summary, the decision analysis article by Stillwaggon et al 7 indicated that prenatal screening and treatment of toxoplasmosis in the United States could be a costsaving approach for congenital toxoplasmosis but only under the assumptions included in the model. Although several sensitivity analyses in their model (including variations for the main assumptions such as incidence of acute maternal infections, cost of tests and life-value equivalent) showed that the results were robust, the implementation of such a screening program would, nevertheless, require a significant reduction in the current cost of screening laboratory tests and significant changes in the structure of the US prenatal care system.…”

Toxoplasmosis, zoonosis parasitaria prevalente en Chile: recuento y desafíos

“…Esto último no se ha alcanzado completamente 67 . Sí se ha establecido que el modelo de Francia aplicado a la realidad de E.U.A., permitiría bajar los costos basado en criterios públicos de mantención de discapacidades de por vida, costos de diagnósticos y tratamientos actuales 11 .…”