Lubezky 1998.

Study characteristics
Patient Sampling	The study included patients with carotid occlusion diagnosed by CDUS. Exclusion criteria: quote "Patients in whom the duplex scan was equivocal, with poor visualization of the ICA, were excluded from the study. Only cases in which a technically satisfactory duplex scanning was obtained were included".
Patient characteristics and setting	148 patients diagnosed with carotid occlusion. 102 male (70%) and 46 female (30%) Age: ranged from 43 to 89 years old (average age was 70 years) 22% were asymptomatic and 88% were symptomatic. Other risk factors for atherosclerosis: 99 patients (67%) had hypertension, 85 (58%) were current or past smokers, 64 (44%) had a history of ischemic heart disease, 56 (38%) had hypercholesterolemia, 44 (30%) had diabetes, and 38 patients (26%) had peripheral vascular disease. Five patients (3%) had a history of neck radiation.
Index tests	DUS Image production: HD13000 system (Advanced Technology Laboratories, Bothell, WA, USA) using a linear 5‐10 MHz, 38 mm transducer Contrast: No Criteria used to determine occlusion: Not specified, only occlusion included
Target condition and reference standard(s)	Reference standard: CTA and DSA Target condition: carotid artery occlusion Criteria used to determine grade of stenosis: only occlusion included Complications: Not described
Flow and timing	Maximum time interval between studies was 30 days.
Comparative
Methods	Study design: Unclear Study location: Israel Year and language of publication: Published in 1998 in English Study period: From 1995 to 1997 Participants enrolled: 148 patients Carotids included in analyses: 148 arteries compared with CTA and 54 arteries compared with DSA
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
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?	Unclear
If a threshold was used, was it pre‐specified?	No
Could the conduct or interpretation of the index test have introduced bias?		High 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?	No
Could the reference standard, its conduct, or its interpretation have introduced bias?		High 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?	No
Were all patients included in the analysis?	Yes
Could the patient flow have introduced bias?		High risk