Cai 2020a.
| Study characteristics | |||
| Patient Sampling | 2‐group study to estimate sensitivity and specificity for detection of active disease
[1] Laboratory‐confirmed COVID‐19 patients (n = 276)
[2] Controls with other infections (n = 167). A third group of healthy controls was used to set thresholds (n = 200) but not estimate accuracy. Recruitment method: NR if patients were consecutive Sample size (viral/COVID cases): 443 (276) Exclusion criteria: none stated |
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| Patient characteristics and setting | [1] Hospital (inpatients); Chongqing Three Gorges Central Hospital, Yongchuan Hospital Affiliated to Chongqing Medical University (CQMU), and The Public Health Center, in Chongqing, China (recruitment dates NR). 168/276 (61%) had fever. Median age 48 (IQR 37‐56; range 0‐84) years, 151/276 (55%) male. 99/276 (36%) reported known exposure
[2] Controls with other infection (n = 167); Second Hospital Affiliated to CQMU and Children’s Hospital Affiliated to CQMU; time NR. Other infections included: influenza A virus (25), respiratory syncytial virus (7), parainfluenza 111 virus (8), influenza B virus (5), adenovirus (6), Klebsiella pneumoniae (8), Streptococcus pneumoniae (3), Mycoplasma (5), Acinetobacter baumannii (10), Candida albicans (2), Staphylococcus aureus (3), Mycobacterium tuberculosis (4), Hepatitis B virus (33), Hepatitis C virus (22), Syphilis (23) and Saccharomycopsis (3) [3] Healthy controls (n = 200), source NR; recruited > 1 year before the outbreak. No further details |
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| Index tests | 1 Ab test, blinding NR Laboratory‐based in‐house luminescent immunoassay (CLIA) using serum samples Measured IgM +IgG. Antigen: peptide from SARS‐CoV‐2 S protein Test threshold: determined as the mean luminescence (CL) value of the 200 normal sera plus 5 folds of SD; cut‐off used ≥ 0.7 CL (for both IgG and IgM). (Determined in the healthy control group) Samples acquired day 2‐day 27 after symptoms. Person applying the test NR. | ||
| Target condition and reference standard(s) | 1. Real time RT‐PCR detection of virus RNA, samples not described. Reference threshold and timing NR. Blinded to index test 2. Healthy controls, pre‐December 2019 | ||
| Flow and timing | Time interval between index and reference: NR. Accuracy results were not disaggregated by time period since point of symptom onset. No missing data, uninterpretable or indeterminate results described Analysis participant‐based | ||
| Comparative | |||
| Notes | Funded by Emergency Project from the Science & Technology Commission of Chongqing; Major National S&T program grant from Science & Technology Commission of China; Grant from the National Natural Science Foundation of China, Grant from the Science & Technology Commission of Yuzhong district, Chongqing. COI (reported or derived): study author employed by BioScience Co. LTD, Tianjin, China Publication status (source): preprint (not peer reviewed) (medRxiv) NOTE: Study author institution reported as BioScience Co. LTD, Tianjin, China (www.bioscience‐tj.com/en/about.php) | ||
| 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? | Unclear | ||
| 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? | High | ||
| DOMAIN 3: Reference Standard | |||
| Is the reference standards likely to correctly classify the target condition? | Unclear | ||
| 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? | No | ||
| 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? | High risk | ||