Emery 2001.

Study characteristics
Patient sampling	Prospective study
Patient characteristics and setting	Study location: California, USA Study period: 1 February 1997 to 30 June 1998 Care setting: level I paediatric trauma centre Mass casualty: no Participants enrolled: 491 Participants included in analysis: 160: 95 boys and 65 girls Age: mean age 9 years 5 months (range 1 month to 18 years) Type of injury: blunt abdominal trauma Injury severity: ISS 5 (IQR 1 to 13) Haemodynamic stability: stable conditions Inclusion criteria: all haemodynamically stable paediatric trauma victims referred for abdominal CT initially underwent rapid screening sonography looking for free fluid Exclusion criteria: not reported
Index tests	Index test: FAST US protocol: scans were usually done immediately before the CT scan (< 15 minutes) Hardware used: Acuson unit (Mountain View, CA), 3‐ to 5‐MHz sector or curved transducer Description of imaging technique: locations: each of the 4 abdominal quadrants and the pelvis (2 longitudinal and transverse images in each of the upper quadrants and 1 longitudinal and transverse image in each of the lower quadrants and midline pelvis). No specific epigastric or pericardial view was obtained. The study was focused to identify free fluid. The amount of fluid (none, trace, small, moderate, or large), location(s), and the degree of bladder filling (empty, partially filled, or full) were recorded.
Target condition and reference standard(s)	Target condition: free fluid and air Reference standard: GE HiSpeed Advantage helical CECT (General Electric Medical Systems, Milwaukee, WI) using non‐ionic IV contrast (Optiray 320 (Mallinckrodt, St Louis, MO)) Description of technique: all CT scans included the abdomen and pelvis using a CT and non‐ionic IV contrast in a standard dose of 2 mL/kg administered in bolus fashion. Slice collimation was either 7 mm or 10 mm depending on the participant’s size with a pitch of 1.3:1.
Flow and timing	Time between US and reference standard: < 15 minutes
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 All tests
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
Was the qualification of the US operator appropriate?	Yes
Was the US hardware (i.e. generation, manufacturer, probe, etc.) up to date?	Yes
Was the US protocol (i.e. 'classic' FAST) appropriate?	Yes
Are there concerns that the definition or performance of the index test (i.e. POC US of trauma) do not match generally accepted, established, or practiced rules or recommendations?	No
		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
Was the qualification of the doctors (i.e. radiologists, surgeons, etc.) determining the reference standard appropriate?	Yes
Was the reference imaging standard (i.e. MDCT‐rows (4 to ≥ 256 slices), contrast‐imaging, etc.) up to date?	Yes
Are there concerns that the definition or performance of the reference tests (e.g. CT, MRI, laparatomy, thoracotomy, autopsy, etc.) do not match generally accepted, established, or practiced rules or recommendations?	No
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Yes
Did all participants receive a reference standard? (Risk of partial verification bias)	Yes
		Low