Jiang 2012.

Study characteristics
Patient sampling	Study design: prospective cohort study. Participants: pregnant women at high risk of fetal aneuploidy presenting for invasive testing selected from the cohort. Inclusion criteria: not reported. Exclusion criteria: not reported.
Patient characteristics and setting	Number enrolled: 903 pregnant women. Number available for 2 x 2 table: 903 pregnant women (whole cohort included in analyses). Setting: 3 centres in Shenzen, China. Recruitment period: June 2009 to August 2010. Ethnicity: Asian. Gestational age range: 10 to 39 weeks. Maternal age range: 20 to 45 years. Relevant tests carried out prior to index test: not reported. Language of the study: English.
Index tests	gNIPT by MPSS on platforms Illumina Genome Analyzer IIx or Illumina HiSeq 2000 by multiplex sequencing. Fetal fraction DNA (range): quality control criteria > 3.5% (1% to 33%). It is not reported if the blood samples for gNIPT were collected before or after reference standard. Cutpoint: 1) Positive if binary hypothesis t score (first hypothesis) > 3 and t score (second hypothesis) < 3 and if logarithmic LR > 1 (autosomal aneuploidy). 2) Positive if t score < ‐2.5 (45,X and 47,XXX) without Chrom. Y representation. 3) Positive if t score > 2.5 combined with estimation of fetal ccfDNA concentration by Chrom. X and Y independently (47,XXY and 47,XYY) for male fetus. Commercial test: NIFTY™ prenatal test by Bejing Genomics Institute (BGI).
Target condition and reference standard(s)	Target conditions: T21, T18, T13, 45,X, 47,XXY, 47,XYY and 47,XXX. Reference standard: fetal karyotype of amniotic fluid.
Flow and timing	It is not reported if the blood samples were obtained prior or after the invasive procedure (reference standard). gNIPT was a second‐tier test. No failed sample reported. No repeated test reported.
Comparative
Aim to study	To develop an advanced gNIPT method based on MPSS.
Funding source or sponsor of the study	Study funded by industry. BGI was involved in the study design, conduct of the study, analysis and interpretation of results.
Informations about the authors contacted	Author was contacted on: 19 May 2016. No reply received from the author.
Notes
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
		High	Low
DOMAIN 2: Index Test MPSS
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
If a threshold was used, was it pre‐specified?	Yes
		Low	Low
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Yes
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Unclear
Did all analysed patients receive the reference standard?	Yes
Were all patients included in the analysis?	Yes
		Unclear