Aldobyany 2020.

Study characteristics
Patient Sampling	Purpose: diagnosis of SARS‐CoV‐2 infection (mild COVID‐19 disease); to determine the diagnostic performance characteristics of the COVID‐19 respiratory triage score Design: cross‐sectional cohort study, retrospective data collection Recruitment: all participants presenting to a tertiary hospital (presenting to ED or clinic) and tested for COVID‐19: participants either self‐presenting due to symptoms (> 50%), or active screening of contacts to COVID‐19 patients or recently travelled (mostly asymptomatic group) Sample size: n = 1435 (340 cases) Inclusion criteria: all participants presented to King Abdullah Medical City and tested for COVID‐19 Exclusion criteria: participants who did not have a documented COVID‐19 respiratory triage score, or presented prior to 2 April 2020
Patient characteristics and setting	Facility cases: positive RT‐PCR for SARS‐CoV‐2 Facility controls: negative RT‐PCR for SARS‐CoV‐2 Country: Saudi‐Arabia Dates: 02 April 2020‐12 September 2020 (date of submission article) Symptoms and severity: mostly asymptomatic, mild or moderate severity Demographics: age: controls mean 39.3 years, cases mean 38.7 years M%/F%: cases 68.5/31.5, controls 55.4/44.6 Exposure history: not specified, > 70% of participants were HCW
Index tests	Saudi CDC COVID‐19 respiratory triage score (exposure risks + fever or recent history of fever, cough (new or worsening), shortness of breath (new or worsening), nausea, vomiting, and/or diarrhoea) Fever Cough Dyspnoea GI symptoms
Target condition and reference standard(s)	TC: SARS‐CoV‐2 infection RS: RT‐PCR for SARS‐CoV‐2 (nasopharyngeal swab)
Flow and timing	Timing not specified
Comparative
Notes	Setting unclear Funding: none declared
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?	No
Did the study avoid inappropriate inclusions?	Yes
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?			Low concern
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?		Unclear risk