Kärk 2012.

Study characteristics
Patient sampling	Retrospective study
Patient characteristics and setting	Study location: Denmark Study period: January 2003 to December 2010 Care setting: hospital emergency department Mass casualty: no Participants enrolled: 405: gender specification not reported Participants included in analysis: 118 Age: not reported for 118 participants Type of injury: blunt abdominal trauma, liver injury Injury severity: not reported Haemodynamic stability: stable and unstable conditions Inclusion criteria: this study included all patients admitted to the institution registered with the ICD‐10 code S36.1 'Injury of the liver or gallbladder' as defined by the WHO, especially abdominal blunt trauma patients Exclusion criteria: patients with iatrogenic lesions of the biliary system
Index tests	Index test: FAST US protocol: the majority of participants were examined by radiologists trained in general abdominal US, and a minority by surgeons trained in FAST Hardware used: not reported Description of imaging technique: recorded findings of intraperitoneal free fluid (if possible in 4 different areas: Morison’s pouch in the right upper quadrant, the perisplenic space in the left upper quadrant, the pericardium of the epigastric region, and the pelvis)
Target condition and reference standard(s)	Target condition: free fluid and air Reference standard: CT (technique specification not reported), explorative laparotomy Description of technique: not reported
Flow and timing	Time between US and reference standard: not reported
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?	Yes
		Unclear	High
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
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?	Unclear
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
		Unclear	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
Was the qualification of the doctors (i.e. radiologists, surgeons, etc.) determining the reference standard appropriate?	Unclear
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
		Unclear	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