Wald 2009.
| Clinical features and settings | Routine screening | |
| Participants | 14,296 participants in whom screening for all markers were measured UK ‐ 2 Hospitals 2003 ‐ 2007 (2004 ‐ 2007 for 1 hospital) Pregnant women Singleton pregnancies Median maternal age 33 years (range 15‐51 years), 20% ≥ 37 years 10‐13 and 14‐22 weeks' gestation |
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| Study design | Retrospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 47 cases Reference standards: karyotyping or follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT (details not reported) First trimester PAPP‐A (details not reported) Second trimester AFP, uE3, hCG, free ßhCG and, at one hospital, inhibin‐A (details not reported) Integrated test (at 1 of the hospitals women were given the option of having only the combined test and earlier test results) Cut‐point 1:150 |
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| Follow‐up | Down's syndrome pregnancies, including those missed by screening, were ascertained from hospital records, cytogenetic laboratories and by linking data with the National Down Syndrome Cytogenetics Register | |
| Aim of study | To present a medical audit of screening using the Integrated test at 2 hospitals | |
| Test characteristics | ||
| Reference standard used | ||
| 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 | Unclear | Unclear if 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 | No details given for test failures/uninterpretable measurements |
| Withdrawals explained? All tests | No | No details of withdrawals given |