Kim 2006.
| Clinical features and settings | Routine screening | |
| Participants | 2570 participants with available outcome data Korea ‐ hospital and womens healthcare centre January 2001 to December 2001 Pregnant women Mean age 29.9 years (SD 3.3 years) Singleton pregnancies 10‐14 weeks' gestation |
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| Study design | Retrospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 31 cases Reference standard: amniocentesis or CVS in 419 patients considered high risk (NT > 2.5, aged > 35 years, positive biochemical test result, history of chromosomal abnormality, fetal structural abnormality at ultrasound or other reason). Follow‐up to birth |
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| Index and comparator tests | First trimester NT (FMF methods) (HDI 3000, ATL, Bothell, WA, USA) 3 measurements taken, largest one used for risk calculation Cut‐off 2.5 mm, 3.0 mm or 95th percentile of each CRL |
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| Follow‐up | Pregnancy outcomes ascertained from obstetric and neonatal medical records of live or stillborn babies Only patients with known pregnancy outcome included in the study 8 patients who terminated their pregnancies because of structural abnormalities on ultrasound with no karyotyping results were excluded. Karyotyping was performed in intrauterine fetal death (n = 4) cases |
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| Aim of study | To determine the value of NT with different cut‐offs for the detection of chromosomal aberrations | |
| 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 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 |