PHE 2020(d) [HCW tested].

Study characteristics
Patient Sampling	Set of studies conducted by PHE and University of Oxford. This extraction relates to a single group study estimating sensitivity alone: ‐ individuals presenting at one of 14 regional drive‐through COVID‐19 NHS test and trace centres as part of the FALCON C‐19 (Facilitating Accelerated Clinical validation Of Novel diagnostics for COVID‐19, 20/WA/0169, IRAS 284229) phase 3b study; those with a positive PCR result were asked to return for a re‐test within 5 days of the original test result. From the originally published report (Nov 2020) it appears that only participants with samples that were positive on PCR at the second sampling were included. PHE 2020(d) [HCW tested] is for health care worker tested samples, and PHE 2020(d) [Lab tested] is for laboratory scientist tested samples See other PHE extractions for other sub‐studies of Innova assay Recruitment: Not stated; presume consecutive Prospective or retrospective: Prospective Number of samples (cases): 479 (479) ; 267 tested by HCWs, 212 tested by laboratory scientists
Patient characteristics and setting	Setting: NHS drive through test and trace centres; no further details Location: 14 regional centres Country: UK Dates: 17 Sept to 23 Oct 2020 Symptoms and severity: Only described for all 421 included participants in PHE 2020(d) [HCW tested] and PHE 2020(d) [Lab tested] combined: Suppl Table 2 reports 40 (9.5%) asymptomatic, 59 (14%) with no data, leaving 322 with >=1 symptom recorded. It is not stated whether symptoms were present at the time of the original swab or at the time of the second sampling therefore data for the asymptomatic group have not been included in analyses . NB: text reports data for 41 asymptomatic and 344 symptomatic from the Phase 3b study (total n = 385) Demographics: For the 421 participants: median age 33 y, 168, 40% male Exposure history: Not stated
Index tests	Test name: Innova SARS‐CoV‐2 Antigen Rapid Qualitative Test Manufacturer: Innova Medical Group Antibody: Not stated Antigen target: Not stated Test method: Not stated Samples used: combined anterior nasal and oropharyngeal swabs (1 stored as a dry swab and 1 swab placed in VTM; swabs were self‐collected Transport media: Dry swab Sample storage: None; immediate testing (delay to testing at PHE for [B] is unclear) Test operator: PHE 2020(d) [HCW tested] HCW on‐site, PHE 2020(d) [Lab tested] Laboratory scientist at PHE Definition of test positivity: Visual line; as per manufacturer Blinding reported: Yes Timing of samples: Not stated
Target condition and reference standard(s)	Reference standard: RT‐PCR; no details. The pre‐print supplementary materials describes using the 'Roche platform' under the Phase 3b heading, and also provides the following text under the Phase 2 evaluation heading "Unless otherwise stated, all RT‐PCR testing was undertaken on the Roche Cobas® 6800 or 8800 system using their proprietary SARS‐CoV‐2 assay as per manufacturer’s instructions (with off‐board lysis using AVL buffer (Qiagen) and 5% Triton‐X100 (Sigma Aldrich)). This assay detects ORF‐1a/b as a SARS‐CoV‐2 specific target, and the E‐gene as a pan‐sarbecovirus target." Definition of non‐COVID cases: Genetic target(s): Not stated Samples used: Appears to be combined NOP swabs in VTM; obtained at same time as second sampling for Ag testing (5 days after 1st positive PCR) Timing of reference standard: As for index test Blinded to index test: Not stated Incorporated index test: No
Flow and timing	Time interval between index and reference tests: appears to be simultaneous (if 2nd PCR result was used). All patients received same reference standard: Yes Missing data: Initial sample of 267 reported, 27 failed, leaving 240 for inclusion however data for only 223 HCW tested samples are provided in the pre‐print (text pg 7). The original report (Nov 2020) documented 16 samples in this cohort that were either PCR‐ (n=15) or void (n=1) presumably at the time of the second sampling (as only PCR+ were invited for Ag testing. Although the numbers don't quite add up, it seems likely that this could explain the difference between the 240 and 223 samples. Uninterpretable results: Failure rates reported as: [A] 28/296, 10.4%; [B] 9/221, 4.2% Indeterminate results (index test): Unclear Indeterminate results (reference standard): Unclear Unit of analysis: Patients
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?	No
Did the study avoid inappropriate exclusions?	Yes
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)
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 (Rapid molecular tests)
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?			High
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	No
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	No
Did all participants receive a reference standard?	Yes
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		High risk