Brochot 2020 [A].

Study characteristics
Patient Sampling	Purpose: Diagnosis of acute and convalescent‐phase COVID‐19 infection Design: Multi‐group study estimating sensitivity and specificity including: [1] patients hospitalised for COVID‐19 (n = 20); [2] non‐hospitalised patients but PCR confirmed with SARS‐CoV‐2 (n = 58); [3] patients participating in screening campaigns, also described as outpatients with no history of SARS‐CoV‐2 infection (n = 62); [4] and samples from patients with a history of other seasonal coronavirus infections (n = 28). Study focused mainly on agreement between evaluated assays; data could be extracted for samples with PCR+ result (from group [1] and group [2]) at two time points and for non‐COVID‐19 cases (group [3]) Recruitment: Unclear Prospective or retrospective: Retrospective Sample size: 168 (78) Further detail: Not further described
Patient characteristics and setting	Setting: Hospital in patients, outpatients and community screening Location: Amiens University medical Center, Amiens Country: France Dates: Not stated Symptoms and severity: Not stated Demographics: Available in the supplement. Could not open the file*** Exposure history: Not stated Non‐Covid group 1: Outpatients with no history of SARS‐CoV‐2 ***Review authors think that some of these have had Covid but have not had it PCR‐confirmed ‐ if you look at Fig 2, quite a number of samples have positive serology results, too many to all be false positives. What we did in this case, was to report the group in item A2 (as publication authors have done) but then we did not use the data because there was apparently no reference standard for them. Source: During pandemic Characteristics: Non‐Covid group 2: Other human coronavirus infections Source: Not clearly described; may be pre‐pandemic Characteristics: Not stated
Index tests	Test name: Assays identified only by manufacturer: [A] Abbott; [B] Biorad; [C] Euroimmun; [D] Liaison; [E] Wantai Manufacturer: [A] Abbott; [B] Biorad; [C] Euroimmun; [D] Liaison; [E] Wantai Antibody: [A] IgG; [B] total antibodies; [C] IgG; [D] IgG; [E] total antibodies Antigen target: [A] nucleocapsid; [B] nucleocapsid; [C] spike 1; [D] spike1/2; [E] receptor binding domain Evaluation setting: Laboratory Test method: [A] CLIA; [B] ELISA; [C] ELISA; [D] CLIA; [E] ELISA Timing of samples: Time pso not given; number of samples by time post‐PCR+ given only for day 31‐50 (n = 21) and > 50 days (n = 14) Samples used: Serum Test operator: Not stated Definition of test positivity: Positivity thresholds were as follows: [A] Abbott >= 1.4; [B] Biorad >= 1; [C] Euroimmun >= 1.1; [D] Liaison >= 15; [E] Wantai >= 1 Samples with a 'doubtful' signal were tested a second time; if the same result was obtained, result was considered negative Blinding reported: Not stated Threshold predefined: Yes, manufacturer defined thresholds used
Target condition and reference standard(s)	Reference standard: PCR; no further details Samples used: Nasopharyngeal swab Timing of reference standard: Not stated Blinded to index test: Not stated Incorporated index test: Not stated Definition of non‐COVID cases: PCR for group 3. Pre‐pandemic for group 4 Samples used: Nasopharyngeal swab Timing of reference standard: Not stated Blinded to index test: Not stated Yes; conducted first (and was basis for selection of samples for testing) 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: None reported Uninterpretable results: None reported Indeterminate results: None reported Unit of analysis: Not stated; referred to selection of 'samples' but also stated that longitudinal data not available (Discussion)
Comparative
Notes	Funding: This work was supported by a grant from the Amiens University Medical Center Publication status: Published paper Source: Journal of Clinical Virology Author COI: Authors declared no COI present
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?	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?			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?	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?	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?	Unclear
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Unclear
Could the patient flow have introduced bias?		High risk