Health-economic aspects of down syndrome screening

Purpose: In Germany every pregnant woman aged 35 or older has to be offered the option of invasive genetic screening. An alternative strategy is provided by combined first trimester screening (FTS) according to Nicolaides. The aim of this study was to investigate the test performance of FTS compared to age-indicated screening (AIS) and assess the economic consequences. Material and Methods: At the Medical University of Hanover 2743 combined FTS procedures were carried out. The PIA Fetal Database program was utilized for risk assessment and all measurements were subsequently recalculated using the NT-module of the JOY software. If the result was suspect, invasive testing was offered. An analysis of costs was calculated on the basis of these test performance parameters. Results: Both FTS methods had a much better test performance with a sensitivity of 85.7% and a false-negative rate (FNR) of 14.3% compared with AIS (sensitivity 42.9%, FNR 57.1%). With a specificity of 97.6% and a false-positive rate (FPR) of 2.5% the JOY software was superior to both the PIA software (specificity 96.5%, FPR 3.5%) and AIS (specificity 96.5%, FPR3.5%) (p < 0.001). If AIS were used as the only test, the cumulative costs in Germany would amount to 385 million Euros. If FTS were carried out together with the PIA software the costs would be 196 million Euros, while the costs would be 178.7 million Euros with the JOY software. Conclusion: The use of AIS is no longer state-of-the-art and AIS should be replaced by more effective screening methods in practice. A direct comparison of all methods found the JOY software to be the most suitable. Its inclusion into standard prenatal care strategies should be discussed.