Moore 2020.

Study characteristics
Patient Sampling	2‐group study to estimate sensitivity and specificity: ‐ samples from symptomatic (fever or cough or shortness of breath) adult and paediatric outpatients, ED patients, and inpatients Recruitment: consecutive (first 94 participants), then all PCR‐positive samples plus the next PCR‐negative sample after each positive sample, to a total of 200 samples Prospective or retrospective: retrospective (participant and sample details extracted from the electronic medical record) Number of samples (samples with confirmed SARS‐CoV‐2): 200 (125)
Patient characteristics and setting	Setting: mixed (outpatients, ED patients and inpatients) Location: Rush University Medical Centre (RUMC) or Rush Oak Park Hospital (ROPH), Chicago Country: USA Dates: 27 March‐9 April 2020 Symptoms and severity: 79 (39.5%) hospitalised including 29 in ICU, 76 (38%) ambulatory care including 55 seen in a designated COVID‐19 screening clinic), and 45 (23%) seen at ED Demographics: mean age 50 years (SD 17 years), 92 (46%) men Exposure history: not stated
Index tests	Test name: ID NOW (no product code) Manufacturer: Abbott Antigen target: RdRp Antibody: N/A Test method: isothermal amplification test Samples used: NP swabs in 3 mL VTM (collection not reported) Transport media: M4‐RT VTM (Remel, Lenexa, KS) Sample storage: stored at 4 °C if all testing could not be completed on the same day; all tests completed within 72 h of collection Test operator: not stated; presume laboratory staff Definition of test positivity: as per manufacturer Blinding reported: not stated Timing of samples: not stated; presumably on presentation but no information on symptom status
Target condition and reference standard(s)	Reference standard: RT‐PCR; 2 methods used in the study modified CDC RT‐PCR (positive result required Ct < 40 for both targets; negative if neither target detected and positive amplification curve for control (RP) gene; inconclusive if only 1 target detected at Ct < 40, and test repeated) Abbott RealTime SARS‐CoV‐2 RT‐PCR (amplification curves reported as detected or not detected) Record review used to verify status of 8 samples positive on RealTime assay and negative (6) or inconclusive (2) on CDC assay (all considered disease‐positive) Definition of non‐COVID cases: single RT‐PCR negative Genetic target(s): N1, N2 N, RdRp Samples used: NP swabs in VTM, as for index test Timing of reference standard: not stated Blinded to index test: not stated Incorporated index test: no
Flow and timing	Time interval between index and reference tests: all 3 tests conducted within 72 h of sample collection All participants received same reference standard: no? (all received both RT‐PCR tests, only discordant results on RT‐PCR had record review) Missing data: none reported, no participant flow diagram reported Uninterpretable results: 2 results were invalid on ID NOW and were not retested (excluded) Indeterminate results (index test): none reported Indeterminate results (reference standard): discordant results between 2 RT‐PCR assays had record review to determine presence/absence COVID‐19 infection Unit of analysis: participants (specimens from 200 unique participants)
Comparative
Notes	Funding: none reported (some reagents supplied from NIH) Publication status: preprint Source: medRxiv Author COI: no COI statement was reported
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Was a case‐control design avoided?	No
Did the study avoid inappropriate exclusions?	Unclear
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?			High
DOMAIN 2: Index Test (Antigen tests)
DOMAIN 2: Index Test (Rapid molecular 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?	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?			High
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
Reference standard does not incorporate result of index test?	Yes
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?	Unclear
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		Unclear risk