Patient sampling items	Patient characteristics and setting items	Index test items	Reference standard items	Flow and timing items	Notes items
A0 Test type (antibody/antigen etc)	COVID patients (or all patients if single group study)
A1 Purpose	B1 Setting	D1.1 Test name	E1 Reference standard for cases including threshold	F1 What was the time interval between index and reference tests?	G1: Funding
A2 Design (and description of groups labelled [1] [2] …)	B2 Location (include name of institution if available)	D1.2 Manufacturer	E2 Samples used	F2 Did all patients receive the same reference standard?	G2: Publication status
A3 Recruitment	B3 Country	D1.3 Antibody targets	E3 Timing of reference standard (preferably since symptom onset only, if not from a different time points)	F3 Missing data	G3: Source (preprint or journal name)
A4 Were cases recruited prospectively or retrospectively?	B4 Dates	D1.4 Antigens used	E4 Was it blind to index test?	F4 Uninterpretable results	G4: Study author COI (including any manufacturer affiliations)
A5 Sample size (virus/COVID cases)	B5 Symptoms and severity	D1.5 Point‐of‐care or laboratory (is the test designed to be used at point‐of‐care or in laboratory, and was it used as point‐of‐care or in laboratory)?	E5 Did it incorporate index test?	F5 Indeterminate results	G5 Comment
A6 Inclusion and exclusion criteria	B6 Demographics	D1.6 Test method		F6 Samples or patients
A7 Comment	B7 Exposure history	D1.7 When were samples taken (preferably since symptom onset only, if not from a different time points)?	E6 Reference standard for non‐cases	F7 Comment
	B8 Comment	D1.8 Samples used	E7 Samples used
	Non‐COVID patients (if additional groups)	D1.9 Who applied the test	E8 Timing of reference standard (preferably since symptom onset only, if not from a different time points)
	C1.1 Group name	D1.10 How was positive defined?	E9 Was it blind to index test?
	C1.2 Source and time	D1.11 Blinded to reference standard	E10 Did it incorporate index test?
	C1.3 Characteristics	D1.12 Threshold predefined	E11 Comment
	C2.1 Group name	D1.13 Comment
	C2.2 Source and time
	C2.3 Characteristics
	C4 Comment