Fox 2011.

Study characteristics
Patient sampling	Prospective study
Patient characteristics and setting	Study location: California, USA Study period: 2004 to 2007 Care setting: level I trauma centre Mass casualty: no Participants enrolled: 475 Participants included in analysis: 357: 230 men and 127 women Age: range 0 to 17 years (more graduation in study) Type of injury: blunt abdominal trauma Injury severity: IQR ISS 4 to 12 Haemodynamic stability: not reported Inclusion criteria: patients with blunt trauma as falls, motor vehicle crashes, automobile versus pedestrian collisions, non‐accidental blunt trauma, and battery Exclusion criteria: no consent to study inclusion, no confirmation of FAST results by CT, penetrating injuries, accidental blunt trauma
Index tests	Index test: FAST US protocol: the FAST exams were performed by emergency medicine residents (62% of total, 51% of total by third‐year emergency medicine residents), attending emergency physicians (21%), and US fellows and surgeons (8% each) Hardware used: B+K Hawk 2102 (Copenhagen, Denmark), SonoSite Titan, or SonoSite Micromaxx (Bothell, WA) US machine with 3.5‐ to 5.0‐MHz curved array (Hawk), 2‐ to 4‐MHz convex array (Titan), or 2‐ to 4‐MHz phased array transducers Description of imaging technique: locations evaluated for free fluid: around the heart and 3 areas of the abdominal–pelvic cavity (hepatorenal, splenorenal, suprapubic)
Target condition and reference standard(s)	Target condition: free fluid and air Reference standard: CECT (technique specifications not reported) or laparotomy Description of technique: by protocol, all eligible participants had FAST at arrival followed by CT of the abdomen and pelvis within 30 minutes, or underwent laparotomy. All participants had CT with IV contrast; oral contrast was routinely used for the first 18 months of the study, but not thereafter.
Flow and timing	Time between US and reference standard: < 30 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?	No
Did the study avoid inappropriate exclusions?	Yes
		Unclear	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?	Unclear
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?	Yes
		Low	High
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?	No
Were all patients included in the analysis?	Yes
Did all participants receive a reference standard? (Risk of partial verification bias)	Yes
		Low