Schaelike 2009.
| Clinical features and settings | Routine screening | |
| Participants | 10,668 participants with complete outcome data Germany ‐ private centre November 2000 ‐ December 2006 Pregnant women Singleton pregnancies Maternal age ≥ 35 years in 31.0% of women 11‐13 weeks' gestation |
|
| Study design | Prospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 59 cases Reference standards: karyotyping or follow‐up to birth |
|
| Index and comparator tests | Maternal age First trimester NT (FMF certified physicians) First trimester PAPP‐A and free ßhCG (Kryptor analyser, Brahms GmbH) Cut‐point 1:300 |
|
| Follow‐up | Information provided by either obstetric departments or obstetricians. Results from CVS and amniocentesis, as well as karyotypes from aborted fetal tissue or from postnatal investigations were used. 3.9% of women were lost to follow‐up and were excluded from the study | |
| Aim of study | To assess the performance of a combined first trimester screening concept for trisomies 21, 18 and 13 applied to a low‐ and high‐risk patient sample in a specialised private centre for prenatal medicine | |
| 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 |