Goh 1996.

Clinical features and settings	Routine screening
Participants	11,964 participants Singapore ‐ University Hospital 1989 to 1992 Pregnant women Singleton pregnancies Median maternal age 35 years (mean 33 years) 12‐22 weeks' gestation
Study design	Cohort
Target condition and reference standard(s)	Down's syndrome: 34 cases Reference standards: karyotyping or follow‐up to birth
Index and comparator tests	Maternal age First trimester and second trimester AFP and hCG (EIA method, kits from Abbot Laboratory, USA) and uE3 (In‐house indirect, extraction radioimmunoassay) Risk cut‐points of 1:250 and 1:384
Follow‐up	No details of methods of follow‐up
Aim of study	To appraise the potential effectiveness of implementing a prenatal screening programme on a local population in Singapore
Test characteristics
Reference standard used
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