O'Reilly 2020a.

Study characteristics
Patient Sampling	Purpose: diagnosis of SARS‐CoV‐2 infection (mild COVID‐19 disease); to determine the clinical and epidemiological predictors of a positive SARS‐CoV‐2 test result and the requirement for intensive respiratory support Design: cross‐sectional cohort study, prospective data collection Recruitment: adult patients who meet testing criteria for COVID‐19 and have a SARS‐CoV‐2 PCR test requested in the ED Sample size: n = 240 (cases = 11) Inclusion criteria: all adults who met the testing criteria for COVID‐19 and who presented at the ED Exclusion criteria: patients who attended the screening clinic and did not present for medical assessment in the ED (no clinical data available)
Patient characteristics and setting	Facility cases: positive RT‐PCR for SARS‐CoV‐2 Facility controls: negative RT‐PCR for SARS‐CoV‐2 Country: Australia Dates: 01 April 2020‐14 April 2020 Symptoms and severity: moderate to severe Demographics: mean age: cases 51 years, controls 61 years M%/F%: cases 72.0/28.0, controls 55.0/45.0 Exposure history: contact with infected person: cases 56%, controls 7%
Index tests	Shortness of breath Cough Change to chronic cough Anosmia/dysgeusia Sore throat Runny nose Fever Fatigue Myalgia Diarrhoea
Target condition and reference standard(s)	TC: SARS‐CoV‐2 infection RS: SARS‐CoV‐2 RT‐PCR test (specimen not specified)
Flow and timing	RS and index tests taken on the same day
Comparative
Notes	Funding: none declared
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?	Unclear
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 (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?	Yes
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