Hammond 2008.

Study characteristics
Patient Sampling	Inclusion criteria: patients with non‐disabling neurology symptoms and an apparent carotid occlusion on DUS Exclusion criteria: patients failing to undergo all exams within 14 days; patients who refused to provide informed consent
Patient characteristics and setting	Not described
Index tests	DUS Image production: Acuson 128 XP10 US machine 7 MHz linear array transducer Contrast: yes. Contrast agent: Levovist (Schering, UK) Criteria used to determine grade of stenosis: quote "Vessels were characterised as definitely occluded (if no flow was seen anywhere within the cervical ICA) or definitely patent (if a flow channel was seen throughout the cervical ICA)".
Target condition and reference standard(s)	Reference standard: DSA Target condition: carotid occlusion Criteria used to determine grade of stenosis: quote "Vessels were characterised as definitely occluded if no contrast could be identified in the line of the cervical ICA or if there was significant discontinuity with backfilling of the siphon and distal ICA from the intracranial vessels". Complications: Not described
Flow and timing	DUS, DSA and MRA were performed within 14 days. Quote "Nineteen vessels were excluded on the basis of incomplete imaging due to patient failure to attend (8 vessels), claustrophobia and inability to tolerate MRA (10 vessels), or refusal to consent to DSA (1 vessel). A further 9 vessels were excluded because there was a delay of > 14 days in completing of their imaging." A confident diagnosis could not be made in 5/31 (16%) vessels, so 24 vessels included in analysis
Comparative
Methods	Study design: Prospective accuracy study. Unclear whether consecutive recruitment Study location: UK Year and language of publication: Published in 2008 in English Study period: Between April 2001 and August 2004 Participants enrolled: 30 patients Carotids included in analyses: 24 arteries
Notes	Only evaluated patients with the diagnosis of occlusion or pseudocollusion
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	No
Could the selection of patients have introduced bias?		High risk
Are there concerns that the included patients and setting do not match the review question?			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
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
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
Could the reference standard, its conduct, or its interpretation have introduced bias?		Unclear risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
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?	No
Could the patient flow have introduced bias?		High risk