Fazel 2002.

Study characteristics
Patient sampling	Type of study: unclear whether prospective or retrospective study. Consecutive or random sample: unclear.
Patient characteristics and setting	Sample size: 40. Females: not stated. Age: not stated. Presentation: Inclusion criteria: People with suspicion of biliary stone disease on the basis of symptoms and signs suggestive of choledocholithiasis (biliary colic, abnormal liver function tests, abnormal transabdominal ultrasound, or a combination). Setting: care setting: not stated, USA.
Index tests	Index test: endoscopic retrograde cholangiography. Further details: Technical specifications: not stated. Performed by: not stated. Criteria for positive diagnosis: not stated.
Target condition and reference standard(s)	Target condition: common bile duct stones. Reference standard: attempted endoscopic extraction of stones in all participants. Further details: Technical specifications: not applicable. Performed by: endoscopists and surgeons. Criteria for positive diagnosis: presence or absence of stones during endoscopic clearance.
Flow and timing	Number of indeterminates for whom the results of reference standard was available: not stated. Number of participants who were excluded from the analysis: not stated.
Comparative
Notes	Attempted to contact the authors in June 2013. Received no replies.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
		High	High
DOMAIN 2: Index Test ERCP
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
		High	High
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
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Unclear
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Unclear
		High