Bhola 2014.

Study characteristics
Patient sampling	Retrospective observational study
Patient characteristics and setting	Country: Australia Setting: Royal Prince Alfred Hospital (tertiary maternity hospital delivering over 5000 newborns a year) Study period: 42‐month period (from April 2008 to December 2011) Inclusion criteria: all newborns (routine neonatal examination) Exclusion criteria: not stated Live birth cohort, n = 19,765 N screened: 18,801 (95.1%) (648 had been admitted to the nursery and did not qualify for screening, 316 missed) Prevalence of CCHD: 0.2 per 1000 live births
Index tests	Pulse oximetry was performed with a Masimo Radical 5 portable oximeter (Masimo Corporation, Irvine, CA, USA) with a reusable probe with disposable Coban tape (1‐inch self‐adherent wrap, manufactured by 3M, Australia). Screening protocol: Site of testing: post‐ductal (foot) Test timing: longer than 24 hours (between 24 and 72 hours of life) Oxygen saturation: functional Threshold: < 95% "If the post‐ductal saturation was 95% or more, the result was assigned as a pass. Readings between 90% and 95% led to a repeat saturation measurement in the next 1–2 hours. If the post‐ductal saturation remained below 95% on repeat testing, the newborn was referred for review and examination by a senior neonatal paediatrician. If the saturation was less than 90%, at any time, the newborn was referred for review by a senior neonatal paediatrician without waiting for a repeat test."
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: database of the Heart Centre for Children at Children’s Hospital at Westmead for any newborns undergoing cardiac surgery or catheter intervention in the first year of life
Flow and timing	Duration of follow‐up: not stated Loss to follow‐up: 316 missed (not performed by the resident, performed but not recorded, screening not completed before early discharge or owing to compliance issues when the new protocol was originally introduced)
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?	Unclear
Did the study avoid inappropriate exclusions?	Unclear
		Unclear	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?	Unclear
Was there at least 28 days of appropriate follow up?	Unclear
Did all patients receive a reference standard?	Yes
		Unclear