Dave 2020.

Study characteristics
Patient Sampling	Purpose: Diagnosis of COVID‐19 infection and prognostication Design: Single‐group study to assess sensitivity [1] RT‐PCR‐positive patients admitted to a tertiary care hospital Recruitment: All RT‐PCR‐positive COVID 19 patients (both symptomatic and asymptomatic) above the age of 18 y admitted in various wards of a dedicated Corona hospital from April 2020 to May 2020 Prospective or retrospective: Unclear Sample size: 100 (100) Further detail: Inclusion: All RT‐PCR‐positive COVID‐19 patients (both symptomatic and asymptomatic) above the age of 18 y Exclusion: (i) patients on steroids, immunosuppressants and chemotherapy (ii) PLHA and other immune‐deficiency diseases (iii) non‐consenting patients
Patient characteristics and setting	Setting: Patients admitted to a tertiary care hospital (dedicated COVID hospital) Location: RNT Medical College, Udaipur, Rajasthan Country: India Dates: April 2020‐May 2020 (2 months) Symptoms and severity: 76 asymptomatic; 17 mild to moderate; 7 severe Demographics: Male 45; female 55 Mean age 37 years Exposure history: Not reported Non‐Covid group 1: NA
Index tests	Test name: Antibody‐based rapid card test (no specific name provided) Manufacturer: SIDAK Life Care Antibody: IgM and IgG Antigen target: Not reported Evaluation setting: POC unclear where used Test method: Lateral flow method (immune chromatographic assay) Timing of samples: days of illness for all 100 patients (74/100 were asymptomatic so must be days post‐positive PCR?): 0‐7 (n = 23) 8‐14 (n = 27) 15‐21 (n = 36) > 21 (n = 14) Samples used: Whole blood (2 drops) Test operator: Not reported Definition of test positivity: (a) Along with C band, if band at zone 1, indicates the presence of IgM (b) Along with C band, if band at zone 2, indicates the presence of IgG (c) Along with C band, if band at zone 1 and 2, indicates the presence of both IgM and IgG Blinding reported: No Threshold predefined: Yes
Target condition and reference standard(s)	Reference standard: RT‐PCR‐positive; according to the protocols by National Institute of Virology, Pune Samples used: Nasopharyngeal/oropharyngeal swab Timing of reference standard: Not stated Blinded to index test: Yes (done prior to the index test) Incorporated index test: No Definition of non‐COVID cases: NA Samples used: NA Timing of reference standard: NA Blinded to index test: NA Incorporated index test: NA
Flow and timing	Time interval between index and reference tests: Not reported All patients received same reference standard: Yes Missing data: Not reported Uninterpretable results: Not reported Indeterminate results: Not reported Unit of analysis: Patients
Comparative
Notes	Funding: Not stated Publication status: Published article Source: Journal of Indian Academy of Clinical Medicine Author COI: No COI declaration
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?	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?			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?	No
If a threshold was used, was it pre‐specified?	Yes
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?			Unclear
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?	Yes
The reference standard does not incorporate the index test	Yes
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?			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