Bouzid 2020.

Study characteristics
Patient Sampling	Purpose: diagnosis of SARS‐CoV‐2 infection (mild COVID‐19 disease); to identify clinical or biological characteristics to help distinguish SARS‐CoV‐2 from other respiratory viruses Design: cross‐sectional cohort study, prospective data collection Recruitment: all consecutive patients admitted through the ED and presenting with respiratory symptoms Sample size: n = 596 (268 cases) (from 03 March 2020) Inclusion criteria: all consecutive patients presenting with an influenza‐like illness (ILI: fever with a temperature > 38.5 °C, malaise, headache, and myalgia; and 1 respiratory symptom (cough, sore throat, and dyspnoea)) and admitted to the hospital through the ED Exclusion criteria: none specified
Patient characteristics and setting	Facility cases: positive SARS‐CoV‐2 test Facility controls: negative SARS‐CoV‐2 test Country: France Dates: 03 March 2020‐30 March 2020 Symptoms and severity: not specified, all patients presented with ILI, 13% needed ICU admission, 13% died Demographics: median age cases 59 years, controls 62 years M%/F%: cases 71.0/29.0, controls 50.0/50.0 Exposure history: not specified
Index tests	Feverishness Hypothermia Chills Sweats Headaches Myalgia Malaise Cough Sore throat Dyspnea Expectoration Chest pain Bilateral cracklings
Target condition and reference standard(s)	TC: SARS‐CoV‐2 infection RS: depending on kit availability, viral investigations were conducted either with the QIAstat‐Dx Respiratory SARS‐CoV‐2 Panel (Qiagen, Hilden, Germany), allowing for the detection of respiratory pathogens plus SARS‐CoV‐2, or with a combination of the RT‐PCR RealStar SARS‐CoV‐2 Kit RUO (Altona Diagnostics, Hamburg, Germany) and rapid multiplex PCR FilmArray RP2 (BioFire, BioMerieux, Marcy‐ L’Etoile, France), specimen not specified
Flow and timing	Index tests and RS both taken at ED admission
Comparative
Notes	Conflicts of interest: DB and BV declare having received past personal fees and grant from Qiagen (Hilden, Germany) Funded by the AP‐HP (Assistance Publique – Hôpitaux de Paris). This study was supported by Qiagen in the form of a grant funding the data management of the RespiFast2 study targeting to assess the impact of respiratory viruses and of discounted equipment and consumables in the context of the COVID‐19 outbreak.
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?	No
Did the study avoid inappropriate inclusions?	Yes
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?			Unclear
DOMAIN 2: Index Test (All 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?	No
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?			Low concern
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
Could the reference standard, its conduct, or its interpretation have introduced bias?		Low risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
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?	No
Were all patients included in the analysis?	Unclear
Could the patient flow have introduced bias?		Unclear risk