Monni 2005.
| Clinical features and settings | Routine screening | |
| Participants | 16,654 participants Italy ‐ single centre 2001‐2004 Pregnant women Median age 32 years (14‐49 years) Singleton pregnancies 10‐14 weeks' gestation |
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| Study design | Prospective cohort | |
| Target condition and reference standard(s) | Down's syndrome: 96 cases Reference standards: karyotyping or follow‐up to birth |
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| Index and comparator tests | Maternal age First trimester NT (FMF methods, No information given regarding machines used) First trimester nasal bone examination (transabdominal ultrasound in mid‐sagittal view) Annual audit of screening performance (medians) |
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| Follow‐up | Outcome at birth as recorded in hospital database (provided by outcome sheets or telephone interviews). Of 32,000 cases in the database, 16,654 (52%) patients had NT, nasal bone assessment and follow‐up data available. Patients without follow‐up data were excluded from the study | |
| Aim of study | To evaluate the feasibility and diagnostic accuracy of fetal NT and nasal bone assessment at 11‐14 weeks for screening of trisomy 21 | |
| 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 | Yes | In 13 cases (1.3%) not possible to ascertain if nasal bone was visible |
| Withdrawals explained? All tests | No | No details of withdrawals given |