Study characteristics
Patient Sampling  Purpose: diagnosis of acute SARS‐CoV‐2 infectionDesign: cross‐sectional, retrospective studyRecruitment: all patients presenting to 1 of 2 EDs, located at an urban teaching hospital, and academic quaternary medical centre, within the same healthcare system who had targeted testing based on clinician's decision during the initial 10 days of test availabilitySample size: n = 283 (29 cases)Inclusion criteria:patients presenting with symptoms related to COVID‐19 infection (fever and cough or shortness of breath)
travel within 14 days to countries with high rates of infection (at that time China, Iran, Italy, Japan, and South Korea) or
risk factors for infection complications (including age or comorbid conditions) or
the patient was a healthcare worker who could potentially expose others at risk and clinician made decision for testing
Exclusion criteria: not specified
Patient characteristics and setting  Facility cases: positive SARS‐CoV‐2 testFacility controls: negative SARS‐CoV‐2 test, visiting the same EDs and being testedCountry: USA (San Diego, CA)Dates: 10 March 2020‐19 March 2020Symptoms and severity:all patients presenting to ED who were eligible for targeted testing (= patients presenting with symptoms related to COVID‐19 infection (fever and cough or shortness of breath)
travel within 14 days to countries with high rates of infection (at that time China, Iran, Italy, Japan, and South Korea) or
risk factors for infection complications (including age or comorbid conditions) or
the patient was a healthcare worker who could potentially expose others at risk
comorbidities 101/235 (43.0%) (cases: 8/27 (29.6%), controls 93/208 (44.7%))
Demographics: age (< 18 years: 0.7%, 18‐64 years: 83.4%, > 65 years: 15.9%); gender: cases M/F%: 55.2/44.8; controls M/F%: 52.8/47.2; all M/F%: 53.0/47.0Exposure history: recent travel (5.5%), 90.6% symptom‐based criteria for testing, no known exposure history based
Index tests  Fever
Target condition and reference standard(s)  TC: SARS‐CoV‐2 infection
RS: Commercial RT‐PCR test ‐ ePLex SARS‐CoV‐2 test (nasopharyngeal swab)
Flow and timing  Probably no time interval between index test and RS, but not specified
Comparative   
Notes   
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?     Unclear 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?     Unclear 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?  Unclear      
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