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. 2020 Jul 7;2020(7):CD013665. doi: 10.1002/14651858.CD013665

Song 2020b.

Study characteristics
Patient Sampling Purpose: to develop a tool for early diagnosis of SARS‐CoV2‐infected patients
Design: cross‐sectional, retrospective, single‐centre (2 time frame study: training ‐ validation data set)
Recruitment: 1311 patients who presented to the First Affiliated Hospital, School of Medicine, Zhejiang University with at least 1 SARS‐CoV‐2 RT‐PCR test
Sample size: n = 304 (73 cases) (= subset of the study including training dataset only)
n = 95 (18 cases) (= validation dataset)
Inclusion criteria

  • All RT‐PCR‐positive cases; 1311

  • All RT‐PCR‐negative patients who came to the First Affiliated Hospital, School of Medicine, Zhejiang University and performed with at least 1 SARS‐CoV‐2 nucleic acid detection for analysis RT‐PCR

  • First 60% of negative outpatients sorted by 'Z‐A' based on Chinese first name from Qingchun District (training dataset), and then final 40% who presented (validation dataset)


Exclusion criteria

  • Asymptomatic patients without history of exposure but had strong willingness for detection

  • Patients with "important" missing data
Patient characteristics and setting Facility cases: positive SARS‐CoV‐2
Facility controls: negative SARS‐CoV‐2
Country: China
Dates: 20 January 2020‐05 February 2020
Symptoms and severity: in positives: non‐severe (n = 31), including mild or moderate patients to severe (n = 42) including severe or critical patients

  • Mild: patients had no pneumonia on imaging (CT)

  • Moderate: patients with symptoms and imaging examination showing pneumonia

  • Severe: patients meet any of the following:

    • respiratory rate ≥ 30/min

    • resting pulse SpO2 ≤ 93%

    • PaO2/FiO2 ≤ 300 mmHg (1 mmHg = 0.133 kPa)

    • multiple pulmonary lobes showing more than 50% progression of lesion in 24‐48 hours on imaging

  • Critical: patients meet any of the following:

    • respiratory failure requiring mechanical ventilation

    • shock

    • combination of other organ failure that requires admission to ICU


Demographics: M/F: cases 46/27, controls 104/127
median age: cases 53.0 years (43.5‐62.0) controls 34 years (29‐49)
Exposure history: Wuhan‐related exposure and or close contact to confirmed COVID‐19 case: cases 40.7%, controls 57.5%
Index tests

  • Fever

  • Cough

  • Expectoration

  • Headache

  • Myalgia or fatigue

  • Chill

  • Rhinobyon/rhinorrhoea

  • Pharyngalgia

  • Dyspnoea

  • Diarrhoea

  • Nausea/vomiting

  • Temperature (maximum)

  • Body temperature

  • SpO2

  • Respiratory rate

  • Heart rate

  • Mean arterial pressure
Target condition and reference standard(s)

  • TC: SARS‐CoV‐2 infection

  • RS: RT‐PCR for SARS‐CoV‐2 (test not specified: "using emergency use authorization approved SARS‐CoV‐2 assays)" (following WHO protocol, 2 target RT‐PCR (ORF1 and N)
Flow and timing Within 3 h for RS, first in‐hospital stay for index tests
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? No    
Was a case‐control design avoided? Yes    
Did the study avoid inappropriate exclusions? Unclear    
Did the study avoid inappropriate inclusions? Yes    
Could the selection of patients have introduced bias?   Unclear risk  
Are there concerns that the included patients and setting do not match the review question?     Low concern
DOMAIN 2: Index Test (All 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? No    
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?     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? 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?     Low concern
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard? Yes    
Did all patients receive the same reference standard? Yes    
Were all patients included in the analysis? Yes    
Could the patient flow have introduced bias?   Low risk