Li 2009.

Study characteristics
Patient sampling	Type of study: prospective study. Consecutive or random sample: unclear.
Patient characteristics and setting	Sample size: 103. Females: 65 (63.1%). Age: 49 years. Presentation: Inclusion criteria: People undergoing cholecystectomy with ≥ 1 of the following features. History of obstructive jaundice. History of biliary pancreatitis. Common bile duct diameter > 10 mm in calibre. Elevated liver function tests. Setting: Department of Surgery, China.
Index tests	Index test: intraoperative cholangiography. Further details: Technical specifications: not applicable. Performed by: surgeon. Criteria for positive diagnosis: not stated.
Target condition and reference standard(s)	Target condition: common bile duct stones. Reference standard: extraction of stones in people with positive intraoperative cholangiography (surgical or endoscopic) and clinical follow‐up of minimum 12 months in people with negative intraoperative cholangiography. Further details: Technical specifications: not applicable. Performed by: surgeons and clinicians. Criteria for positive diagnosis: extraction of stones in people with positive intraoperative cholangiography (surgical or endoscopic) and clinical follow‐up of minimum 12 months in people with negative intraoperative cholangiography.
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?	No
		High	High
DOMAIN 2: Index Test IOC
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?	Unclear
		High	High
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?	No
Were all patients included in the analysis?	Unclear
		High