Narinx 2020.

Study characteristics
Patient Sampling	Study design: patients with suspected COVID‐19, all symptomatic
Patient characteristics and setting	Age group: adults, perhaps also children Setting: outpatient
Index tests	Index test(s): chest CT (low dose); ultrasound of lungs (POCUS) Defintion for positive diagnosis on CT: scored as suggestive for or inconsistent with COVID‐19 infection based on the presence of clinical manifestations as presented by Ng et al. (Ng 2020) and Shi et al. (Shi 2020) Defintion for positive diagnosis on ultrasound: positive if one or more BLUE points showed a positive B‐line parameter Level of training of readers: radiologist Prevalence: 0.2
Target condition and reference standard(s)	Reference standard: RT‐PCR, no other details provided
Flow and timing
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?	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 (Chest CT)
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?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 2: Index Test (Chest X‐ray)
DOMAIN 2: Index Test (Ultrasound of the lungs)
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?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Low 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?	Unclear
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?	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