Model inputs and economic value of NIPT for fetal aneuploidy screening.

FP(s), false positives; CVS, chorionic villus sampling; NIPT, non-invasive prenatal testing ^ NIPT values that correspond to the range applied to each input variable. These values can be compared to the $744 value assigned to the set of baseline model inputs. ¥ Alternative scenario showing results when all initial screening is performed in the second trimester. * Baseline invasive testing rates for true positives were 73% for trisomy 21 and 90% for trisomy 13, trisomy 18, and monosomy X. These rates were not changed when the invasive rate for false-positives was adjusted. † Baseline termination rates for trisomy 21, trisomy 18, trisomy 13, and monosomy X were 87%, 81%, 90%, and 65%, respectively [34]. ‡ The range evaluated for cost variables was baseline minus 40% to plus 20%. The cost of first trimester screening ($369) was a buildup of all the individual components (see Results). § The range of lifetime costs of an affected child was baseline ±20%; the upper and lower range values for each indication were modified together. ˅Most of the variability is attributable to lifetime costs for Down syndrome (see text). Model inputs and economic value of NIPT for fetal aneuploidy screening.