Table 1 Key model inputs (base case)
Parameter | Value | Source |
|---|---|---|
Pregnant population attending the NHS for pregnancy follow-up | 78.40% | Estimated from EUSTATa and ASPb |
Twin pregnancies | 2.30% | ASP |
Pregnant population rejecting the screening | 0.01% | ASP |
Pregnant population stopping the screening | 0.02% | ASP |
Prevalence of Down Syndrome | 0.43% | ASP |
First and second trimester screening | ||
1st and 2nd trimester screening uptake | 78.38% | Estimated |
1st trimester screening tests performed | 96.85% | ASP |
Week 11 | 33% | Estimated |
Week 12 | 34% | Estimated |
Week 13 | 33% | Estimated |
2nd trimester screening tests performed | 3.15% | ASP |
High-risk pregnant population (NT > 3.5 mm) for T21 | 0.41% | ASP |
Prevalence of T21 | 1:10 | Hulstaert et al. [20] |
Sensitivity | 89.75% | ASP |
Specificity | 95.65% | ASP |
NIPT | ||
NIPT as first line screening uptake | 78.38% | Assumption |
NIPT repeated | 4% | Hulstaert et al. [20] |
NIPT without results (test failure) | 2% | Hulstaert et al. [20] |
Sensitivity | 99.30% | Benn et al. [25] |
Specificity | 99.84% | Benn et al. [25] |
Invasive testing (CVS or amniocentesis) | ||
IT rejected | 4.82% | ASP |
Procedure-related fetal loss | 0.69% | ASP |
Hospitalization for amniotic fluid leakage | 1% | Hulstaert et al. [20] |
Sensitivity | 100% | Assumption |
Specificity | 100% | Assumption |
Pregnancy termination after T21 diagnosis | 94% | ASP |
Miscarriage in the total pregnant population | Ammon Avalos et al. [19] | |
Week 10 | 5% | |
Week 12 | 2.50% | |
Week 14 | 1.50% | |
Miscarriage in the T21 pregnant population | Snijders et al. [28] | |
Week 10 | 36% | |
Week 12 | 30% | |
Week 14 | 25% | |
Costs | ||
Primary care appointment with the midwife | €24 | 2015 Osakidetza feesc |
Collection of the blood sample | €19 | 2015 Osakidetza fees |
Management of the request for the blood test | €5 | 2015 Osakidetza fees |
PAPP-A | €14 | 2015 Osakidetza fees |
β-hCG | €14 | 2015 Osakidetza fees |
AFP | €14 | 2015 Osakidetza fees |
Ultrasound monitoring of amniocentesis procedure | €338 | 2015 Osakidetza fees |
Amniotic fluid karyotyping | €451 | 2015 Osakidetza fees |
CVS karyotyping | €840 | 2015 Osakidetza fees |
Unit cost of NIPT | €550 | Estimation |
Pregnancy termination (DRG 381) | €1825 | 2015 Osakidetza fees |
Hospitalization due to amniotic fluid leakage (DRG 886) | €1577 | 2015 Osakidetza fees |