Loconsole 2020.

Study characteristics
Patient Sampling	Purpose: Diagnosis of acute phase infection Design: Prospective cohort study (n=819) Single‐group study to estimate sensitivity and specificity [1] PCR‐positive patients ‐ 148 [1a] < 7 days of symptoms ‐ 99 [1b] > 7 days of symptoms ‐ 44 [1c] Asymptomatic patients ‐ 5 [2] PCR‐negative patients ‐ 671 Recruitment: Consecutive (but convenient) Prospective or retrospective: Prospective Sample size: Total ‐ 819 PCR +ve ‐ 148 Further detail: Inclusion ‐ Consecutive patients presenting to the Emergency department between 23 March and 21 April 2020 [1] All patients with a positive PCR [1a] Patients with a positive PCR and symptoms < 7 days [1b] Patients with a positive PCR and symptoms > 7 days [1c] Patients with a positive PCR and no symptoms [2] PCR‐negative patients
Patient characteristics and setting	Setting: Emergency department Location: Policlinico Hospital of Bari, Italy Country: Italy Dates: 2020‐03‐23 to 2020‐04‐21 Symptoms and severity: 721/819 (88%) with respiratory symptoms (undefined). No indication of severity 98/819 (12.0%) no respiratory symptoms. Demographics: Median age ‐ 66 (IQR 52‐80) Male ‐ 454/819 (55.4%) Exposure history: Not stated Non‐Covid group 1: NA Source: NA Characteristics: NA Non‐Covid group 2: NA Source: NA Characteristics: NA
Index tests	Test name: SARS‐CoV‐2 VivaDiagTM serological assay Manufacturer: Vivacheck Biotech, Hangzhou, China Antibody: IgM and/or IgG Antigen target: Not stated Evaluation setting: POC (All samples were analysed at the Laboratory of Molecular Epidemiology and Public Health of the Hygiene Unit of the Policlinico Hospital Bari, which is the Regional Reference Laboratory for surveillance and diagnosis of SARS‐CoV‐2) Test method: Lateral flow immunoassay (colloidal gold) (CGIA) Timing of samples: [1] PCR‐positive patients ‐ 148 [1a] < 7 days of symptoms ‐ 99 [1b] > 7 days of symptoms ‐ 44 [1c] Asymptomatic patients ‐ 5 Samples used: 10 micL of plasma or whole blood Test operator: Not stated Definition of test positivity: Visible line, read at 15 min If the quality control line “C” and the detection IgM and/or IgG lines were coloured, then the test was interpreted as positive for IgM and/or IgG anti‐SARS‐CoV‐2 antibodies. Blinding reported: Not stated (done at the same time as rt‐PCR so maybe yes as results were quicker) Threshold predefined: Yes
Target condition and reference standard(s)	Reference standard: RNA was extracted using the Microlab Nimbus automated extraction system (Seegene, Seoul, Republic of Korea), according to the manufacturer’s instructions. A commercial multiplex real‐time PCR kit (AllplexTM 2019‐nCoV Assay, Seegene, Seoul, Korea) was then used to detect the E, RdRP, and N genes of SARS‐CoV‐2. Results were considered positive when two or three genes were identified. The WHO Real‐time RT‐PCR protocol was used to confirm results when samples resulted positive for one gene. Samples used: Nasal and pharyngeal swabs Timing of reference standard: Prospective cohort study [1a] < 7 days of symptoms ‐ 99 [1b] > 7 days of symptoms ‐ 44 [1c] Asymptomatic patients ‐ 5 All patients ‐ on admission to ED Blinded to index test: Not stated Incorporated index test: No Definition of non‐COVID cases: Contemporaneous [2] Negative SARS‐COV2 PCR RNA was extracted using the Microlab Nimbus automated extraction system (Seegene, Seoul, Republic of Korea), according to the manufacturer’s instructions. A commercial multiplex real‐time PCR kit (AllplexTM 2019‐nCoV Assay, Seegene, Seoul, Korea) was then used to detect the E, RdRP, and N genes of SARS‐CoV‐2. Results were considered positive when two or three genes were identified. The WHO Real‐time RT‐PCR protocol was used to confirm results when samples resulted positive for one gene. Samples used: Nasal and pharyngeal swabs Timing of reference standard: No respiratory symptoms ‐ 93 0‐7 days pso ‐ 415 > 7 days pso ‐ 52 Unknown time with symptoms ‐ 111 Performed on admission to ED Blinded to index test: Not stated Incorporated index test: No
Flow and timing	Time interval between index and reference tests: Simultaneous All patients received same reference standard: Yes Missing data: Not stated Uninterpretable results: Not stated, possibly none (If the quality control line “C” was not coloured, the test was interpreted as invalid and repeated) Indeterminate results: None Unit of analysis: One sample per patient
Comparative
Notes	Funding: None This research received no external funding. Publication status: Published paper Source: International Journal of Environmental Research & Public Health Author COI: None The authors declare no 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?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
Did the study avoid inappropriate inclusions?	Yes
Could the selection of patients have introduced bias?		Low risk
Are there concerns that the included patients and setting do not match the review question?			Low concern
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?			Unclear
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	No
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?		High 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?	Yes
Did all participants receive a reference standard?	Unclear
Were results presented per patient?	Yes
Could the patient flow have introduced bias?		Unclear risk