Zayet 2020a.

Study characteristics
Patient Sampling	Purpose: diagnosis of SARS‐CoV‐2 infection (mild COVID‐19 disease); to compare the symptoms of patients with positive and negative SARS‐CoV‐2 RT‐PCR results and to determine the sensitivity, specificity, positive predictive value and negative predictive value for each of these symptoms in regard to SARS‐CoV‐2 RT‐PCR Design: retrospective cohort study Recruitment: all adult patients (≥ 18 years) who presented for possible COVID‐19 at the outpatient department Sample size: n = 217 (95 cases) Inclusion criteria: all adult patients (≥ 18 years) who presented for possible COVID‐19 at the outpatient department Exclusion criteria: pregnant women, children (< 18 years) and patients with dementia (unable to report functional symptoms)
Patient characteristics and setting	Facility cases: patients with suspected COVID‐19 with a positive RT‐PCR Facility controls: patients with suspected COVID‐19 with a negative RT‐PCR Country: France Dates: 30 March 2020‐03 April 2020 Symptoms and severity: mild to moderate severity Demographics: mean age: cases: 39.8 years, controls: 39.6 years. Gender: % female cases: 83.2%, controls: 86.9% Exposure history: not specified (mostly HCWs)
Index tests	Fever Myalgia/arthralgia Headache Cough Dyspnoea Dysgeusia Anosmia Rhinorrhea GI symptoms
Target condition and reference standard(s)	TC: SARS‐CoV‐2 infection RS: PCR for SARS‐CoV‐2 (nasopharyngeal swabs)
Flow and timing	Not specified
Comparative
Notes	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?	Unclear
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