Corbett 2000.

Study characteristics
Patient sampling	Prospective study
Patient characteristics and setting	Study location: California, USA Study period: June 1995 to February 1996 Care setting: level I paediatric trauma centre Mass casualty: no Participants enrolled: 81: gender specification not reported Participants included in analysis: 47 Age: mean age 9 years (range 2 to 7 years) Type of injury: abdominal and pelvic trauma Injury severity: ISS 9.0 (IQR 2.5 to 13) Haemodynamic stability: not reported Inclusion criteria: all children for whom paediatric trauma service consultation was requested and for whom a designated ultrasonographer was available were included. Trauma service consultation was requested on those with moderate to severe injuries judged by the emergency physician to require additional evaluation. Exclusion criteria: conversely, patients ≥ 18 years, those receiving minor trauma that was not felt to require trauma service evaluation, and those for whom a designated ultrasonographer was not available
Index tests	Index test: US US protocol: consecutive children requiring further emergency department evaluation by the paediatric trauma service received a rapid emergency department US examination during their initial resuscitation. US examinations were performed by 17 different emergency medicine residents and attending physicians. Hardware used: Scanner 200 (Pie Medical, Boca Raton, FL) using a 3.5 or 5.0 curvilinear probe Description of imaging technique: 7 views were examined: subxiphoid, right upper quadrant oblique and coronal, left upper quadrant oblique and coronal, pelvic transverse and pelvic longitudinal
Target condition and reference standard(s)	Target condition: free fluid and air Reference standard: CT (technique specification not reported), laparotomy Description of technique: the decision to take a participant for laparotomy or to the CT scanner was made by the trauma team captain based on the usual clinical, laboratory, and radiographic (but not US) findings. CT scans were considered positive if the presence of free fluid was recorded in the radiologists' interpretation. Laparotomies were considered positive if free fluid was noted in the operative note. Other surgical or diagnostic procedures capable of showing the presence of free fluid were also reviewed.
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?	No
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?	Yes
If a threshold was used, was it pre‐specified?	Yes
Was the qualification of the US operator appropriate?	No
Was the US hardware (i.e. generation, manufacturer, probe, etc.) up to date?	Yes
Was the US protocol (i.e. 'classic' FAST) appropriate?	No
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?	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?	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