Blaivas 2005.

Study characteristics
Patient sampling	Prospective, single‐blinded study
Patient characteristics and setting	Study location: Georgia, USA Study period: September 2003 to May 2004 Care setting: level 1 trauma centre Mass casualty: no Participants enrolled: 176: 100 men and 76 women Participants included in analysis: 176 Age: > 17 years Type of injury: abdominal and chest trauma Injury severity: not reported Haemodynamic stability: not reported Inclusion criteria: blunt trauma patients receiving a FAST examination followed by chest radiography and CT of the chest and/or abdomen and pelvis. Patients who had chest tube placement prior to CT scan were included in the analysis, and the presence of pneumothorax was considered to be verified if a rush of air was heard when the chest tube was inserted. Exclusion criteria: no completed examination for any reason
Index tests	Index test: FAST US protocol: 4 locations of each hemithorax (anterior second intercostal space at the midclavicular line, fourth intercostal space at the anterior axillary line, sixth intercostal space at the midaxillary line, and sixth intercostal space at the posterior axillary line) Hardware used: SonoSite 180PLUS (Bothell, WA) using a 4‐ to 2‐MHz microconvex broadband transducer Description of imaging technique: US images were obtained parallel to ribs at the rib interspaces. Depth settings were minimised to approximately 5 cm to optimise magnification of the superficial structures being imaged. Power Doppler was used to enhance the sonologist’s ability to identify pleural sliding whenever the sliding lung sign was not easily detected. Absence of the sliding lung sign at the midclavicular point anteriorly or at the fourth interspace at the anterior axillary line was considered indicative of a small pneumothorax; absence of the sliding lung sign at the midaxillary line, a medium pneumothorax; and absence of the sliding lung sign in the posterior axillary line, a large pneumothorax.
Target condition and reference standard(s)	Target condition: free fluid and air Reference standard: multigated CT scanner using 5‐mm thick slices and portable, supine anteroposterior chest radiographs (technique specification was not reported) Description of technique: all examinations (US, CT, radiography) were performed with the participant in the supine position
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	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