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Table 4 Detection rate for a fixed false-positive rate: Empirical results

From: First trimester screening for trisomy 21 in gestational week 8-10 by ADAM12-S as a maternal serum marker

  DR
(95% CI)
(i) maternal age, PAPP-A & free B-hCG 76.5
(69.4, 83.7)
(ii) maternal age, PAPP-A, free B-hCG & ADAM12-S 73.7
(67.7, 79.6)
(iii) maternal age, PAPP-A, free B-hCG & NT 95.8
(94.6, 97.1)
(iv) maternal age, PAPP-A, free B-hCG, NT & ADAM12-S 92.9
(88.0, 97.8)
(v) maternal age, PAPP-A & ADAM12-S 61.6
(52.1, 71.1)
(vi) maternal age, PAPP-A, ADAM12-S & NT 83.2
(77.7, 88.8)
  1. Results for first trimester screening test with and without ADAM12-S. These results are empirical values, standardised to a reference maternal age population (UK 2000 to 2002).
  2. Detection rates for fetal trisomy 21 at a fixed false-positive rate of 5% are given. Figures in brackets are 95% confidence intervals. Reduction in DR when ADAM12-S is added to first trimester biochemistry and when ADAM12-S is added to the combined test. Substantial reduction in DR when free B-hCG in (i) is replaced with ADAM12-S to give (v) and when free B-hCG in (iii) is replaced with ADAM12-S to give (vi).