Billaud 2020.

Study characteristics
Patient Sampling	Single group study to estimate sensitivity and specificity: ‐ teachers (n=90) and students (n=419) screened for COVID‐19 as part of a cluster investigation (n=509) Recruitment: Not stated; appears to be open to all Prospective or retrospective: Prospective
Patient characteristics and setting	Setting: Screening Location: College, Lyon Country: France Dates: September 16 and 17 Symptoms and severity: 166/509, 32.6% symptomatic including 152/419 (36%) students Demographics: Mean, median age Students 21.6y, 21y (18 to 37y) Teachers 47.2y, 49y (26 to 64y) Exposure history: Outbreak investigation
Index tests	Test name: Described as "ABBOTT SARS‐COV2 Antigenic Test"; presumed to be Panbio COVID‐19 Ag Test Manufacturer: Abbott Antibody: Not stated Antigen target: Not stated Test method: Not stated Samples used: NP; collected by firefighters Transport media: None used Sample storage: n/a; tested immediately on site Test operator: Not stated Definition of test positivity: Visual line; as per manufacturer Blinding reported: Yes, performed first Timing of samples: Not stated but includes people >7 days pso
Target condition and reference standard(s)	Reference standard: RT‐PCR; SARS‐COV‐2 (Thermofisher) Definition of non‐COVID cases: As for cases; single negative Genetic target(s): Not stated Samples used: NP (paired) Timing of reference standard: As for index Blinded to index test: Not stated Incorporated index test: No
Flow and timing	Time interval between index and reference tests: Simultaneous All patients received same reference standard: Yes Missing data: 47 missing, including 11 uninterpretable Uninterpretable results: 11 uninterpretable on Ag test Indeterminate results (index test): None reported Indeterminate results (reference standard): None reported Unit of analysis: Patients
Comparative
Notes	Funding: Not stated, public funding Publication status: Published Source: Report accessed via SFM Microbiologie website Author COI: None
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
Did the study avoid inappropriate inclusions?	Yes
Could the selection of patients have introduced bias?		Low risk
Are there concerns that the included patients and setting do not match the review question?			Low concern
DOMAIN 2: Index Test (Antigen 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?			Unclear
DOMAIN 2: Index Test (Rapid molecular tests)
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	No
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
Reference standard does not incorporate result of index test?	Yes
Could the reference standard, its conduct, or its interpretation have introduced bias?		High 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?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	No
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		High risk