Schreibman 2011.

Study characteristics
Patient sampling	Cross‐sectional cohort (screening cohort + surveillance cohort); prospective single‐centre study.
Patient characteristics and setting	Participants: 37 participants (18 screening, 19 surveillance); 28 male, mean age 56 years (range 21 to 78 years) Baseline diagnosis: aetiology: 11 alcohol; 8 non‐alcoholic steatohepatitis; 7 HCV; 5 alcohol + HCV; 6 other Disease severity: Child‐Pugh score A 23; Child‐Pugh score B 9; Child‐Pugh score C 5. Co‐morbidity: not available. Geographical location of the study: USA. Inclusion criteria: men aged > 18 years, or women aged > 18 years with a negative pre‐procedure pregnancy test or of non‐reproductive potential; inpatient or outpatient; able to provide informed consent. Exclusion criteria: pregnancy; presence of a known Zenker's diverticulum; swallowing disorder; known intestinal diverticulum; suspected intestinal obstruction or stricture; pseudo‐obstruction; active variceal bleeding; presence of a cardiac pacemaker or implanted electro‐medical device; suspected or known Crohn's disease, presence of ileostomy.
Index tests	Index test: capsule endoscopy (PillCam ESO) Criteria for oesophageal varices: according to the North Italian Endoscopic Club (NIEC 1988). Operator: blinded investigator and assessed using the same criteria.
Target condition and reference standard(s)	Target condition: any and large oesophageal varices. Reference standard: oesophago‐gastro‐duodenoscopy. Criteria for oesophageal varices: as defined by the New Italian Endoscopic Club (NIEC 1988). Prevalence of the target condition: 91% (31/34 participants).
Flow and timing	Uninterpretable results: 3 cases not included in the analysis (in 2 participants, no capsule results were obtained due to capsule malfunction and inappropriate connection of the transmitter. In 1 participant, the capsule did not remain in the oesophagus long enough to provide adequate images).
Comparative
Notes	Observer variation: no data on observer variation were reported. Uninterpretable results: 3 cases not included in the analysis. Side effects or complications: no side effects or complications were described. Type of publication: full text.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
Did the study enrol only patients with suspected oesophageal varices not until diagnosed?	No
		High	Low
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
		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
		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?	No
		High