Ewer 2011.

Study characteristics
Patient sampling	Prospective multicenter study with consecutive enrollment of participants
Patient characteristics and setting	Country: United Kingdom Setting: 6 obstetrical units in the West Midlands Study period: February 2008 to January 2009 Inclusion criteria: asymptomatic newborns (gestation > 34 weeks) Study includes newborns in whom congenital heart defects were suspected antenatally after midtrimester ultrasonography. Exclusion criteria: Newborns with symptoms suggestive of cardiac disease that were detected before screening Livebirth cohort, n = 26,513 (3768 missed, 2005 declined, 685 ineligible) N screened: 20,055 (75.6%) Prevalence of CCHD: 1.2 per 1000 live births
Index tests	Pulse oximetry was performed with the Radical‐7 pulse oximeter with reusable probe LNOP Y1 (Masimo, Irvine, CA, USA). Screening protocol: Site of testing: pre‐ductal (right hand) and post‐ductal (either foot in non‐specified order) Test timing: within 24 hours (median age at testing of 12.4 hours for the full cohort) Oxygen saturation: functional Threshold: < 95% "A saturation of less than 95% in either limb or a difference of more than 2% between the limb saturation readings (if both were ≥ 95%) was judged to be abnormal. Clinical examination was expedited if an abnormal test result was obtained. If this examination was unremarkable, oximetry was repeated 1to 2 hours later. If abnormalities of the cardiovascular system were detected with expedited examination, or saturations remained abnormal during a second test, the newborn were classified as test positive."
Target condition and reference standard(s)	Target condition: critical congenital heart defects (ie, death or requiring invasive intervention before 28 days) All infants with hypoplastic left heart, pulmonary atresia with intact ventricular septum, simple transposition of the great arteries, or interruption of the aortic arch All infants dying or requiring surgery within the first 28 days of life with coarctation of the aorta, aortic valve stenosis, pulmonary valve stenosis, tetralogy of Fallot, pulmonary atresia with ventricular septal defect, or total anomalous pulmonary venous connection Reference standard(s): Reference standard used for positive pulse oximetry results: echocardiography Reference standard used for negative pulse oximetry results: clinical follow‐up, use of cardiology databases and congenital anomaly registries
Flow and timing	Duration of follow‐up: up to 12 months Loss to follow‐up: none (n analyzed: 20,055)
Comparative
Notes	Funding: National Institute for Health Research Health Technology Assessment (NIHR HTA) program (project number 06/06/03)
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Did the study avoid inappropriate exclusions?	Yes
		Low	Low
DOMAIN 2: Index Test Pulse oximetry
If a threshold was used, was it pre‐specified?	Yes
Were the index test results interpreted without knowledge of the results of the reference standard?	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?	Unclear
		Low	Low
DOMAIN 4: Flow and Timing
Were all patients included in the analysis?	Yes
Was there at least 28 days of appropriate follow up?	Yes
Did all patients receive a reference standard?	Yes
		Low