Domain	1. Participant selection	2. Index test	3. Reference standard	4. Flow and timing
Signalling questions and criteria	Q.1: "Was a consecutive or random sample of participants enrolled?" Yes ‐ If the study reports on a consecutive or a random selection of participants. No ‐ if the study reports on another form of selection of participants. Unclear ‐ if the study does not report on how the participants were enrolled. Q.2: "Was a case‐control design avoided?" Yes ‐ if the case‐control design was avoided. No ‐ if the study was a case‐control. Unclear ‐ if the study design was not clear. Q.3: "Did the study avoid inappropriate exclusions?" Yes ‐ if the study definitions of exclusion criteria are appropriate (i.e. previous bleeding or treatment for oesophageal varices) and all exclusions are reported. No ‐ if exclusion criteria are inappropriate and exclusions are not reported. Unclear ‐ if the study does not report causes of exclusions.	Q.1: "Were the index test results interpreted without knowledge of the results of the reference standard?" Yes ‐ if the study reports that results of the index test were interpreted without the knowledge of results of the reference standard. No ‐ if the study reports that results of the index test were interpreted with results of the reference standard. Unclear ‐ if the study does not report information about blinding of results of the index test and reference standard. Q.2: "If a threshold was used, was it prespecified?" Yes ‐ if the threshold used was reported in the methods section. No ‐ if the study reports that the threshold was chosen during the data analysis stage (e.g. maximum of Youden index). Unclear ‐ if the study does not report information about threshold selection.	Q.1: "Is the reference standard likely to correctly classify the target condition?" Yes ‐ if the reference standard correctly classifies oesophageal varices (according to common grading scores or systems detailed in "Reference Standard" section). No ‐ if there is some doubt whether the reference standard classifies oesophageal varices. Unclear ‐ if the study does not report on the reference standard used. Q.2: "Were the reference standard results interpreted without knowledge of results of the index test?" Yes ‐ if the study reports that results of the reference standard were interpreted without knowledge of results of the index test. No ‐ if the study reports that results of the reference standard were interpreted with results of the test index. Unclear ‐ if the study does not report information about blinding of results of the reference standard and the index test.	Q.1: "Was there an appropriate interval between the index test and the reference standard?" Yes ‐ if the interval between the index test and the reference standard was less than 3 months. No ‐ if the interval was longer than 3 months. Unclear ‐ if the study does not report the interval between the index test and the reference standard. Q.2: "Did all participants receive the same reference standard?" Yes ‐ if the study has only one reference standard for all participants (OGD with appropriate classification of oesophageal varices). No ‐ if the study has more than one reference standard. Unclear‐ if the study is not clear about the reference standard used. Q.3 "Were all participants included in the analysis?" Answer: Yes ‐ if all enrolled participants were included in the analysis (even in the case of uninterpretable index test result). No ‐ if any participant was excluded from the analysis for any reason. Unclear ‐ if it is not clear about exclusions of participants from the analysis.
Risk of bias	Could the selection of participants have introduced bias? Low risk: "Yes" for all signalling questions. High risk: "No" or "Unclear" for at least one signalling question.	Could the conduct or interpretation of the index test have introduced bias? Low risk: "Yes" for the signalling question. High risk: "No" or "Unclear" for the signalling question.	Could the reference standard, its conduct, or its interpretation have introduced bias? Low risk: "Yes" for all signalling questions. High risk: "No" or "Unclear" for at least one signalling question.	Could the participant flow have introduced bias? Low risk: "Yes" for all signalling questions. High risk: "No" or "Unclear" for at least one signalling question.
Concerns about applicability	Are there concerns that the included participants and setting do not match the review question? Low concern: Participants included in the review represent participants for whom the test is used in clinical practice. High concern: Participants included in the review differ from participants for whom the test is used in clinical practice.	Are there concerns that the index test, its conduct, or interpretation differ from the review question? High concern: The index test, its conduct, or interpretation of the index test differs from the way it is used in clinical practice. Low concern: The index test, its conduct, or interpretation of the index test does not differ from the way it is used in clinical practice.	Are there concerns that the target condition as defined by the reference standard does not match the question?	‐