Fragkou 2020.

Study characteristics
Patient Sampling	Purpose: Diagnosis of current acute‐phase infection Design: Two‐group study to estimate sensitivity and specificity [1] Hospitalised confirmed COVID‐19 cases (n = 26) [2] Asymptomatic healthcare volunteers with negative rRT‐PCR (n = 18) Group [2] had < 25 samples and was excluded from our review. Recruitment: Not stated Prospective or retrospective: Prospective Sample size: 44 (26) of which 16 (16) were eligible for our review Further detail: [1] Hospitalised symptomatic patients with rRTPCR‐confirmed COVID‐19 infection [2] Hospital asymptomatic volunteers, with no clinical symptoms for the past month, with negative SARS‐CoV‐2 rRT‐PCR at the day of sampling and no reported “close contact” history (based on the ECDC definitions for confirmed cases and close contacts) [1] and [2] adults (≥ 18 years old) No additional exclusion criteria were applied.
Patient characteristics and setting	Setting: Hospital inpatients Location: Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece Country: Greece Dates: 30th March 2020 and 6th April 2020 Symptoms and severity: Mild: 8/26; moderate: 8/26; severe and/or critical: 10/26 Demographics: 65.9 ± 15.4 years old, male 57.7% 0‐7 days pso (n = 5): 81.6 ± 11.8 years 7‐14 days pso (n = 11): 68.2 ± 9.4 years > 14 days pso (n = 10): 55.5 ± 15.2 years Exposure history: Not stated Non‐Covid group 1: [2] Pre‐pandemic healthy Source: Asymptomatic healthcare volunteers from a tertiary teaching hospital between 30th March 2020 and 6th April 2020 Characteristics: Adults; hospital staff; no clinical symptoms for the past month, with negative SARS‐CoV‐2 rRT‐PCR at the day of sampling and no reported “close contact” history (based on the ECDC definitions for confirmed cases and close contacts) 45.6 ± 10.1 years old, male 33.3%
Index tests	Test name: (COVID‐19) IgG/IgM Test Kit Manufacturer: Lansion Biotechnology Co., Ltd. (Nanjing, PR China) Antibody: IgG and IgM Antigen target: Not stated Evaluation setting: POCT performed as POC (actual clinical setting) Test method: dry fluorescence immunoassay via a portable analyser Timing of samples: < 7 days: 5/26 7‐14 days: 11/26 > 14 days: 10/26 Samples used: Capillary whole blood: finger‐prick, 5 μL of whole blood was collected in a micropipette and delivered on a test strip. Test operator: Not stated Definition of test positivity: Manufacturer’s cut‐off ≥ 0.04 mIU/mL for both IgG and IgM antibodies; cut‐off of IgM ≥ 0.05 mIU/mL and IgG ≥ 0.10 mIU/mL; cut‐off of IgM ≥ 0.08 mIU/mL and IgG ≥ 0.19 mIU/mL Blinding reported: Not stated Threshold predefined: yes for manufacturer's cut‐off, no for the other cut‐offs
Target condition and reference standard(s)	Reference standard: rRT‐PCR for SARS‐CoV‐2: using the VIASURE SARS‐CoV‐2 Real Time PCR Detection Kit (CerTest Biotec SL, Zaragoza, Spain) Samples used: Nasopharyngeal and/or oropharyngeal swabs; lower respiratory tract samples (e.g. bronchoalveolar lavage or aspirates, sputum, etc.) were also accepted. Timing of reference standard: Not stated Blinded to index test: yes, prior index test Incorporated index test: no Definition of non‐COVID cases: rRT‐PCR for SARS‐CoV‐2 and clinical symptoms, using the VIASURE SARS‐CoV‐2 Real Time PCR Detection Kit (CerTest Biotec SL, Zaragoza, Spain) Samples used: Nasopharyngeal and/or oropharyngeal swabs Timing of reference standard: negative SARS‐CoV‐2 rRT‐PCR at the day of sampling Blinded to index test: unclear Incorporated index test: no
Flow and timing	Time interval between index and reference tests: [1] Not stated [2] Same day All patients received same reference standard: yes Missing data: Not stated Uninterpretable results: Not stated Indeterminate results: No Unit of analysis: Patients
Comparative
Notes	Funding: For PCF: Supported by Doctorate scholarship by the State Scholarships Foundation (IKY), Partnership Agreement (PA) 2014‐2020, co‐financed by Greece and the European Union (European Social Fund‐ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014‐2020" Consumables, test strips and the reader were provided for free by Lansion Biotech. Publication status: Published paper Source: In Vivo Author COI: The authors declared that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was a case‐control design avoided?	No
Did the study avoid inappropriate exclusions?	Yes
Did the study avoid inappropriate inclusions?	No
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 (All tests)
DOMAIN 2: Index Test (Antibody 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?			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
The reference standard does not incorporate the 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?	Unclear
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