Study characteristics
Patient Sampling  Purpose: diagnosis of SARS‐CoV‐2 pneumoniaDesign: cross‐sectional multicentre prospective studyRecruitment: hospitalised pneumonia patientsSample size: n = 53 (20 cases)Inclusion criteria: suspected SARS‐COV‐2 pneumonia patients, defined as having pneumonia after chest CT (with 1 of the 2 following criteria met: fever or respiratory symptoms, normal or decreased WBC counts/decreasedExclusion criteria: not defined
Patient characteristics and setting  Facility cases: confirmed case: a positive SARS‐COV‐2 nucleotides result either by metagenomic sequencing or RT‐PCR assay for nasopharyngeal swab specimensFacility controls: pneumonia patients confirmed not to be infected by SARS‐Cov2 (2 PCR tests, 2 days in between)Country: ChinaDates: 22 January 2020‐19 February 2020Symptoms and severity: suspected SARS‐COV‐2 pneumonia (NCP): having pneumonia after chest CT with 1 of the 2 following criteria met: fever or respiratory symptoms, normal or decreased WBC counts/decreased lymphocyte counts, and a travel history or contact with patients with fever or respiratory symptoms from Hubei Province or confirmed cases within 2 weeksDemographics: median age cases 37 years, controls 39 years, gender distribution cases (M/F: 50/50), controls (M/F: 48.5/51.5)Exposure history: not specified
Index tests  Fever
Dry cough
Diarrhoea
Fatigue
Headache
Vomiting
Abdominal pain
Target condition and reference standard(s)  TC: COVID‐19 pneumonia
RS: a positive SARS‐COV‐2 nucleotides result either by metagenomic sequencing or RT‐PCR assay for nasopharyngeal swab specimens, repeated after 2 days if negative on day 0
Flow and timing  Time interval not specified. Reference standard at day 0 and day 2, index tests from electronic medical records but stated at pneumonia onset
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?  Unclear      
Was a case‐control design avoided?  Yes      
Did the study avoid inappropriate exclusions?  Unclear      
Did the study avoid inappropriate inclusions?  No      
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?        High
DOMAIN 2: Index Test (All tests)
Were the index test results interpreted without knowledge of the results of the reference standard?  Unclear      
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?  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