Schuchter 2002.
| Clinical features and settings | Routine screening | |
| Participants | 4802 participants Austria ‐ single institution December 1997 to April 2000 Singleton pregnancies Pregnant women 13.0% > 35 years 10‐12 weeks' gestation |
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| Study design | Prospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 14 cases Reference standards: CVS and amniocentesis (offered to patients with increased risk (> 1:400) at first trimester screening. CVS recommended when NT > 3.5 or when women did not want to wait until the 15th week for amniocentesis), or follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT (transabdominal transducer, 5‐MHz curvilinear Transducer, Acuson, Mountain View), cut‐point 2.5 mm First trimester PAPP‐A and free ßhCG (done radioimmunologically, kits by Ortho Clinical Diagnostics) Combined risk cut‐point 1:250 |
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| Follow‐up | Patients without follow‐up information (n = 92, 2%) were excluded from the study. 27 women with spontaneous abortions were also excluded from the study | |
| Aim of study | To determine the detection rate of the combined test, NT alone and maternal age alone in a non‐selected population at a false positive rate of about 5% | |
| Notes | ||
| Table of Methodological Quality | ||
| Item | Authors' judgement | Description |
| Representative spectrum? All tests | Yes | Routine screening of typical pregnant population |
| Acceptable reference standard? All tests | Yes | Karyotyping or follow‐up to birth |
| Partial verification avoided? All tests | Yes | All patients received a reference standard |
| Differential verification avoided? All tests | No | Choice of reference standard depended on index test results |
| Incorporation avoided? All tests | Yes | Reference standard was independent of the index test |
| Reference standard results blinded? All tests | No | Reference standard interpreted with knowledge of index test results |
| Index test results blinded? All tests | Yes | Index test interpreted without knowledge of reference standard results |
| Relevant clinical information? All tests | Yes | Information available as would be in standard clinical practice |
| Uninterpretable results reported? All tests | No | No details given for test failures/uninterpretable measurements |
| Withdrawals explained? All tests | Yes | Women not attending visits were excluded from the study |