Martinaud 2020.

Study characteristics
Patient Sampling	Purpose: Diagnosis of current acute‐phase infection or current convalescent‐phase infection Design: Multi‐group study to estimate sensitivity and specificity [1] Confirmed COVID patients (n = 161) [1a] Confirmed COVID patients for "clinical sensitivity" experiment (n = 101) [1b] Confirmed COVID patients for "analytical accuracy" experiment (n = 60) [2] Cross‐reactivity panel (n = 59) [3] Pre‐pandemic, healthy donors (n = 500) Recruitment: Not stated Prospective or retrospective: Retrospective Sample size: 720 (161) of which 682 (123) were eligible for our review. Further detail: Inclusion: [1a] PCR‐confirmed COVID patients with a medical record of the date of symptomatic onset admitted to Military Medical Center, Percy [1b] Patients positive by RT‐PCR and more than 3 weeks after the symptoms onset [2] Sera obtained from patients positive for IgG and IgM against Dengue virus and Chikungunya virus, for HBsAg or anti−HCV, rheumatoid factor, monoclonal proteins, Abs against malaria, Abs against syphilis, IgG and IgM against EBV and IgG against CMV [3] Archived serum samples from healthy donors, obtained in March 2019 Exclusions not stated
Patient characteristics and setting	Setting: [1a] Hospital inpatients [1b] Not stated Location: [1a] Military Medical Center Percy, Clamart, France [1b] Unclear: Serum samples used in this study were obtained from the Medical Laboratory of the Military Medical Centers Percy (Clamart, France), Bégin (Saint‐Mandé, France) and Laveran (Marseille, France) and from the Military Biomedical Research Institute (Marseille, France). Country: [1] France Dates: [1] Not stated Symptoms and severity: [1a] 58/101 severe (= hospitalised, see results section); 43/101 non‐severe [1b] Not stated Demographics: [1] Not stated Exposure history: [1] Not stated Non‐Covid group 1: [2] Cross‐reactivity panel Source: Not stated Characteristics: Patients positive for IgG and IgM against Dengue virus (n = 5) and Chikungunya virus (n = 5), for HBsAg or anti−HCV (n = 5), rheumatoid factor (n = 5), monoclonal proteins (n = 10), Abs against malaria (n = 10), Abs against syphilis (n = 10), IgG and IgM against EBV (n = 4) and IgG against CMV (n = 5) Non‐Covid group 2: [3] Pre‐pandemic healthy Source: Healthy blood donors, obtained in March 2019 (possibly from the Blood Donation Screening Laboratory, French Military Blood Institute, Clamart, France) Characteristics: Healthy
Index tests	Test name: MosaiQ™ COVID‐19 antibody microarray Manufacturer: Quotient Antibody: IgM and IgG Antigen target: Spike S1‐protein Evaluation setting: Laboratory Test method: Solid‐phase photometric immunoassay Timing of samples: [1a] < 14 days pso: 38/101 14‐20 days pso: 33/101 > 20 days pso: 30/101 [1b] > 20 days pso: 60 samples Samples used: Serum Test operator: Not stated Definition of test positivity: Not stated Blinding reported: yes (as qualitative output) Threshold predefined: yes (qualitative output)
Target condition and reference standard(s)	Reference standard: SARS‐CoV‐2 infection was confirmed by PCR in samples from the respiratory tract according to French guidelines, threshold not stated Samples used: samples from the respiratory tract (nasopharyngeal) Timing of reference standard: Not stated Blinded to index test: yes, prior to index test Incorporated index test: no Definition of non‐COVID cases: [2] Unclear [3] Pre‐pandemic Samples used: [2] Not stated [3] Pre‐pandemic Timing of reference standard: [2] Not stated [3] Pre‐pandemic Blinded to index test: yes, prior to index test Incorporated index test: no
Flow and timing	Time interval between index and reference tests: Not stated All patients received same reference standard: no Missing data: Yes (38 COVID samples < 14 days pso and 8 samples from "Analytical accuracy" experiment excluded from our review) Uninterpretable results: Not stated (in another experiment, there were 5 samples flagged with a data reduction error (DRE) making the result unavailable) Indeterminate results: 1 borderline result mentioned in Table 4. This sample was twice repeated and found negative on both occasions and finally concluded as negative. Unit of analysis: Unclear
Comparative
Notes	Funding: Not stated Publication status: Published paper Source: Journal of Clinical Virology Author COI: Not stated
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?	Yes
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Low 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?	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?	No
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Unclear
Could the patient flow have introduced bias?		High risk