Saegerman 2021.

Study characteristics
Patient Sampling	Purpose: diagnosis of SARS‐CoV‐2 infection (mild COVID‐19 disease); to develop a clinical decision support tool for diagnosis of COVID‐19 in hospitals Design: cross‐sectional cohort study, prospective data collection Recruitment: all patients directed to the triage centres of 2 university hospital EDs Sample size: n = 2152 (573 cases) Inclusion criteria: all suspected patients directed to the triage centres (no definition of 'suspected') Exclusion criteria: patient with missing data in clinical records or missing RT‐PCR result
Patient characteristics and setting	Facility cases: positive RT‐PCR for SARS‐CoV‐2 Facility controls: negative RT‐PCR for SARS‐CoV‐2 Country: Belgium Dates: 02 March 2020‐15 June 2020 Symptoms and severity: not specified, clinical suspicion at presentation Demographics: mean age: cases 58 years, controls 52 years M%/F%: cases 48.7/51.3, controls 42.2/57.8 Exposure history: not specified
Index tests	Dyspnoea Chest pain Rhinorrhoea Sore throat Dry cough Wet cough Diarrhoea Headache Myalgia Fever Anosmia
Target condition and reference standard(s)	TC: SARS‐CoV‐2 infection RS: SARS‐CoV‐2 RT‐PCR test (specimen not specified)
Flow and timing	Index tests and RS both taken at presentation
Comparative
Notes	Funded by the Liège University Hospital
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?			Low concern
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?	Yes
Were all patients included in the analysis?	Yes
Could the patient flow have introduced bias?		Low risk