Maymon 2005.
| Clinical features and settings | Routine screening | |
| Participants | 595 participants Israel January 1999 ‐ January 2004 Pregnant women Mean age, healthy 30.3 years (SD 4.5), Down's syndrome 33.7 years (SD 4.9) Singleton pregnancies 11‐14 weeks' gestation and second trimester screening |
|
| Study design | Case‐control study | |
| Target condition and reference standard(s) | Down's syndrome: 24 cases Reference standards: amniocentesis (recommended for women with higher risk on first or second trimester testing) or follow‐up to birth |
|
| Index and comparator tests | Maternal age First trimester NT (11‐14 weeks) First trimester PAPP‐A and free ßhCG (methods detailed in Maymon 2001) (some analysed retrospectively from banked samples) Second trimester PAPP‐A and free ßhCG (methods detailed in Maymon 2001) |
|
| Follow‐up | Delivery outcome obtained by telephone interview or medical records. Information was available for all uneventful pregnancies and delivery outcomes. It is unclear whether information on terminations of pregnancy or miscarriages was available. | |
| Aim of study | To evaluate the cross‐trimester multiple marker correlation and the minimum marker combination needed for detecting various chromosomal aneuploides | |
| 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 |