Rozenberg 2002.
| Clinical features and settings | Routine screening | |
| Participants | 9118 participants France ‐ 2 tertiary and 4 primary referral centres March 1994 ‐ December 1997 Pregnant women Median age 30.5 years (18‐37 years) Singleton pregnancies 12‐14 and 14‐17 weeks' gestation |
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| Study design | Prospective cohort | |
| Target condition and reference standard(s) | Down’s syndrome: 21 cases Reference standards: amniocentesis offered to patients with NT > 3 mm or serum marker risk was >1:250. Follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT in 98.6% of women (FMF methods) Second trimester free ßhCG (beta hCG ELISA immunoradiometric assay) and AFP (AFP ELISA immunoradiometric assay) in 91.1% of women Both NT and biochemical testing in 60.4% of women |
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| Follow‐up | Details of follow‐up not reported. 3.4% of patients were lost to follow‐up and were excluded from the study. This included 113 women (1.2%) with miscarriages | |
| Aim of study | To assess the performance of combined first trimester sonographic screening and second trimester serum screening | |
| Test characteristics | ||
| Reference standard used | ||
| Notes | Includes cost effectiveness analysis | |
| 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 | Yes | NT was not able to be measured in 93 women (1.5%) |
| Withdrawals explained? All tests | No | No details of withdrawals given |