Brameld 2008.

Clinical features and settings	Routine screening
Participants	22,280 participants with complete screening results and outcome data August 2001 ‐ October 2003 Australia ‐ State‐wide screening programme evaluation Pregnant women Median maternal age 31 years (range 14‐47 years), 20% ≥ 35 Singleton pregnancies 10‐14 weeks' gestation
Study design	Retrospective cohort
Target condition and reference standard(s)	Down's syndrome: 60 cases Reference standards: karyotyping or follow‐up to birth
Index and comparator tests	Maternal age First trimester PAPP‐A, free ßhCG and NT (details not reported) Risk cut‐point 1:300
Follow‐up	Data on outcome from the Western Australia Midwives data collection, Birth Defects Registry and hospital morbidity and mortality data
Aim of study	To identify first trimester indicators of adverse pregnancy outcomes
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