Dini 2020.

Study characteristics
Patient Sampling	Study design: patients with suspected COVID‐19, symptomatic or asymptomatic
Patient characteristics and setting	Age group: ≥ 70 years of age Setting: outpatient
Index tests	Index test(s): ultrasound of lungs (POCUS); no further details provided Definition for positive diagnosis on ultrasound: scoring system: non‐coalescent B‐lines, coalescent and with hyperechoic non‐consolidated state Level of training of readers: unclear Prevalence: 0.6
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?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	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 (Chest CT)
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?	Unclear
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Unclear 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