Perez‐Garcia 2020(b).

Study characteristics
Patient Sampling	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
Patient characteristics and setting	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
Index tests	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
Target condition and reference standard(s)	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
Flow and timing	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
Comparative
Notes	See main entry for this study for characteristics and QUADAS‐2 assessment (Perez‐Garcia 2020(a))
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?	No
Did the study avoid inappropriate exclusions?	Yes
Did the study avoid inappropriate inclusions?	Unclear
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?			Low concern
DOMAIN 2: Index Test (All tests)
DOMAIN 2: Index Test (Antibody 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?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Unclear 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?	Unclear
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
The reference standard does not incorporate the index test	Unclear
Could the reference standard, its conduct, or its interpretation have introduced bias?		Unclear risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Unclear
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
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		Unclear risk