Schuchter 2001.
| Clinical features and settings | Routine screening | |
| Participants | 9342 participants Austria ‐ single institution January 1994 to December 1998 Pregnant women Mean maternal age 28 years (range 15‐46 years), 10.7% ≥ 35 years 10‐13 weeks' gestation |
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| Study design | Retrospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 19 cases Reference standards: CVS (offered to patients with first trimester NT > 3.5 mm), amniocentesis (offered to patients with first trimester NT 2.5‐3.4, high risk on second trimester serum testing (> 1:250) and those > 35 years) or follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT (all women) (5‐MHz transducer, Acuson Corp) Second trimester AFP, E2 and hGC (triple test) offered to patients not undergoing first trimester invasive testing (99.7% of women) (AMERLEX‐M 2nd Trimester kits, Ortho Clinical Diagnostics) |
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| Follow‐up | Patients included in study if they were delivered in the same hospital where they were screened. It is stated that all newborns were examined for malformations by a paediatrician after delivery | |
| Aim of study | To evaluate screening for trisomy 21 in a low risk population utilising a combination of NT measurement in the first trimester and the triple test in the second trimester | |
| Test characteristics | ||
| Reference standard used | ||
| Notes | Women having miscarriages were excluded from the study | |
| 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 women 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 | Details given for test failures/uninterpretable measurements |
| Withdrawals explained? All tests | No | No details of withdrawals given |