Valinen 2007.
| Clinical features and settings | Routine screening | |
| Participants | 7534 participants Finland ‐ screening programme 2002‐2004 Pregnant women Singleton pregnancies Mean maternal age 29.6 years, 18.6% ≥ 35 years 10‐12 weeks' gestation |
|
| Study design | Retrospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 30 cases (24 underwent NT as well as biochemical testing) Reference standards: karyotyping or follow‐up to birth |
|
| Index and comparator tests | Maternal age First trimester NT (trained nurses, midwives and doctors) (4765 women) First trimester PAPP‐A and free ßhCG (details not reported) (all women) Cut‐point 1:250 |
|
| Follow‐up | Contacted chromosome laboratory at the department of clinical genetics in the Oulu university clinic and the Finish Register of Congenital Malformation and the National Research and Development Centre for Welfare and Health | |
| Aim of study | To compare the efficacy of both separate and combined maternal serum testing and fetal NT measurement in the first trimester screening for Down's syndrome in northern Finland | |
| 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 |