de‐Wahl Granelli 2009.

Study characteristics
Patient sampling	Prospective study with consecutive enrollment of participants
Patient characteristics and setting	Country: Sweden Setting: 5 maternity units in West Götaland Study period: July 2004 to March 31, 2007 Inclusion criteria: all newborn infants Exclusion criteria: Admitted to neonatal special care units Live birth cohort, n = 46,963 (7064 excluded owing to rolling start of study or admission to neonatal intensive care) Eligible, n = 39,899 (Östran n = 13,455, Mölndaln n = 8953, Trollhättan n = 7019, Borås n = 5382, Skövde n = 5090) Excluded, n = 1470 ‐ refusal (19), oximeter failure (18), staff shortage (2), incomplete record of screening results (39) or of physical examination (1392) N screened: 38,429 (flowchart page 4) Prevalence of CCHD: 0.7 per 1000 live births
Index tests	Pulse oximetry was performed with a pulse oximeter Radical SET, version 4 (average time set on 8 seconds) with multisite LNOP YI sensors, Masimo, Irvine, CA, USA Screening protocol: Site of testing: pre‐ductal (palm of right hand) and post‐ductal (either foot) Test timing: longer than 24 hours Oxygen saturation: functional Threshold: < 95% "When both pre‐ductal and post‐ductal oxygen saturation was < 95% or the difference between the two measurements was > 3% (≥ 2 standard deviations of interobserver measurement variability) the baby was provisionally considered to be screening positive, but a repeat measurement was performed. Babies with three repeated positive measurements were supposed to have an echocardiogram performed the same day according to the study protocol, but with some babies scheduled for early discharge only two pulse oximetry screenings were managed before the discharge examination was performed. Babies were considered screening positive until a measurement not fulfilling screening positive criteria was obtained. If saturation ≤ 90% the newborn was referred for an echocardiogram the same day."
Target condition and reference standard(s)	Target condition: congenital heart disease Reference standard(s): Reference standard used for positive pulse oximetry results: echocardiography Reference standard used for negative pulse oximetry results: mortality data of the National Board of Forensic Medicine (information on all deaths due to undiagnosed cardiovascular malformations in children younger than 1 year in Sweden born during the study)
Flow and timing	Duration of follow‐up: not stated Inconclusive results: 73 (results for only 1 site [34], oxygen saturation < 90% but not optimal [39]) N analyzed: 39,821
Comparative
Notes
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?	No
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
		Unclear	Low
DOMAIN 4: Flow and Timing
Were all patients included in the analysis?	No
Was there at least 28 days of appropriate follow up?	Yes
Did all patients receive a reference standard?	Yes
		Low