Shamsollahi 2020.

Study characteristics
Patient Sampling	Purpose: Two‐group study to evaluate the sensitivity and specificity of a rapid serological test for diagnosis of active or previous COVID‐19 using serum samples Design: [1] 114 RT PCR‐confirmed COVID‐19 patients in hospitals affiliated to Tehran University of Medical Sciences in 2020 [2] 198 frozen serum specimens taken from healthy people in summer and autumn 2019 (pre‐COVID‐19) From group [1], time split 0‐19 days pso was excluded from our review (n = 31). Recruitment: COVID‐19 cases were PCR‐confirmed patients in hospitals affiliated to Tehran University of Medical Sciences in 2020; test‐negative controls were a random sample of frozen serum specimens from healthy people participating in a Tehran University of Medical Sciences Employees COHORT study, taken in summer and autumn 2019 (months before reporting the first case of COVID‐19 by China) Prospective or retrospective: Unclear Sample size: 312 (114) of which 312 (83) were eligible for our review Further detail: No more details available
Patient characteristics and setting	Setting: RT‐PCR‐confirmed COVID‐19 cases in several hospitals ‐ unclear whether inpatient or outpatient Location: Several hospitals affiliated to Tehran University of Medical Sciences Country: Iran Dates: Unclear Symptoms and severity: Not stated Demographics: Average age: 44.0 (± 12.1) years Exposure history: Not stated Non‐Covid group 1: Pre‐pandemic negative controls Source: healthy people participating in a Tehran University of Medical Sciences Employees COHORT study, taken in summer and autumn 2019 Characteristics: Average age: 39.2 (± 8.0) years
Index tests	Test name: “VivaDiag” COVID‐19 IgM/IgG Manufacturer: VivaChek Inc., China Antibody: IgM, IgG Antigen target: Not stated Evaluation setting: POC test; unclear where testing was done for cases; as negative controls were frozen samples, these must have been done in a laboratory Test method: Not stated (Seemed to be colloidal gold from website) Timing of samples: 5‐53 days (mean: 27.9) pso 0‐19 days pso: 31/114 (27.2%) 20‐39 days pso 65/114 (57.0%) 40+ days pso: 18/114 (15.8%) Samples used: 10 μL (whole) blood for cases or frozen serum for pre‐pandemic samples Test operator: Not stated Definition of test positivity: Not stated ; "Based on kit instructions" Visual‐based Blinding reported: No; tests appeared to have been conducted separately for known positives and for known negatives (which had to be thawed before testing) Threshold predefined: Based on kit instructions (visual‐based)
Target condition and reference standard(s)	Reference standard: RT‐PCR ‐ no threshold reported Samples used: Not stated Timing of reference standard: Not stated Blinded to index test: Yes. For cases, samples were already PT PCR‐confirmed when index test used. Incorporated index test: No Definition of non‐COVID cases: Pre‐pandemic blood samples. No report of these being tested by RT‐PCR Samples used: 10 μL blood Timing of reference standard: Pre‐pandemic blood samples. Blinded to index test: Yes. For controls, blood samples were drawn months before the study. Incorporated index test: No
Flow and timing	Time interval between index and reference tests: Not stated for cases; pre‐pandemic controls All patients received same reference standard: No (PCR test for cases, pre‐pandemic samples for controls) Missing data: Not stated Uninterpretable results: Not stated Indeterminate results: Not stated Unit of analysis: 1 sample per patient.
Comparative
Notes	Funding: Not stated; VivaDiag kit donated to Tehran University of Medical Sciences (TUMS) by the Ministry of Health and Medical Education (MOHME) Publication status: Preprint, now published Source: Preprint server ‐ medRxiv Journal (Archives of Iranian Medicine) Author COI: The authors declared no conflict of interest.
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?	Unclear
Did the study avoid inappropriate inclusions?	No
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?			High
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?	No
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		High risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Unclear
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?	Yes
The reference standard does not incorporate the index test	Yes
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?			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?	Yes
Did all participants receive a reference standard?	Unclear
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		High risk