Study characteristics
Patient Sampling  Purpose: diagnosis COVID‐19 pneumoniaDesign: cross‐sectional, retrospective, single‐centre studyRecruitment: patients admitted to ED with history of exposure to COVID‐19Sample size: n = 132 (cases = 7)inclusion criteria: all patients admitted to the fever clinic of the ED of the First medical center, Chinese People's Liberation Army General Hospital (PLAGH) in Beijing with the epidemiological history of exposure to COVID‐19 according to WHO interim guidanceExclusion criteria: < 14 years old, no other criteria specified
Patient characteristics and setting  Facility cases: among clinically suspected patients: those with a positive RT‐PCRFacility controls: clinically non‐suspected patients + suspected patients with negative RT‐PCRCountry: ChinaDates: 14 January 2020‐9 February 2020Symptoms and severity: all patients admitted, with exposure history to COVID‐19, so all levels of severity; days from illness onset until admission (median, IQR): 2.0 (1.0‐5.0); patient population with general mild disease and limited presence of comorbidities (range 0%‐2.3% (COPD))Demographics: age: controls median 40.0 years (IQR 32.5‐54.5), cases median 39.0 years (IQR 37.0‐41.5)M%/F%: cases 71.4/28.6, controls 63.2/36.8Exposure history: epidemiological history of exposure to COVID‐19 (as per WHO guidance)
Index tests  Heart rate
Diastolic BP
Systolic BP
Fever (former: median only on all and cases ‐ no control median given)
Highest temperature
Cough
Shortness of breath
Muscle ache
Headache
Sore throat
Rhinorrhoea
Diarrhoea
Nausea
Vomiting
Chills
Shiver
Expectoration
Abdominal pain
Fatigue
Palpitation
Target condition and reference standard(s)  TC: COVID‐19 pneumonia
RS: in‐house RT‐PCR (E‐gene) ‐ at 4 institutions
Flow and timing  Index test and RS both taken on admission
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?  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 (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?     High 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?  Yes      
Could the patient flow have introduced bias?     High risk