Table 1

Summary of characteristics of included studies, stratified by method of serological testing

No of studiesNo of participantsNo of studiesNo of participantsNo of studiesNo of participantsNo of studiesNo of participants
Peer reviewed:        
Geographical location:        
 Denmark1112162- 116
 United Kingdom190190--  
 United States2774180--167
Clinical setting:        
 Inpatient only11130791508113119116
 Inpatient and outpatient21703349  --
 Not reported21041577826312124
Study design:        
Time from symptom onset to index test§:        
  First week61727190541--
 Second week723991955105--
 Third week or later515992155328--
Accuracy at level of patient or sample:        
Population for estimating specificity‡‡:        
 Stratified12-14 8-  
Samples collected before covid-19 epidemic698553841330132
Samples collected during covid-19 epidemic in individuals not suspected of having covid-19¶6890328042296--
Individuals with suspected covid-19 but RT-PCR negative result--63784167133
Individuals with confirmed other viral infection**32591521167--
Mix of above15191322144--

ELISA=enzyme linked immunosorbent assay; LFIA=lateral flow immunoassay; CLIA=chemiluminescent immunoassay; RT-PCR=reverse transcriptase polymerase chain reaction.

  • * Includes enzyme immunoassay, fluorescence immunochromatographic assay, liquid phase immunoassay.

  • Cassaniti et al15 includes two distinct populations, patients who were triaged or admitted to hospital, with different study design (cohort and case-control). This study as two different cohorts, hence sum of number of studies across LFIA rows is 18.

  • One study was poorly reported, and it was difficult to classify study design.

  • § First week range: 0-7 days (one cohort with 0-10 days is counted in this group); second week: 7-14 days; third week: 15 days or more.

  • †† Patients could have contributed more than one sample, and analyses did not account for correlation.

  • ‡‡ Numbers include samples and patients. Some studies reported more than one type of population to access specificity.

  • Includes studies where timing was unclear.

  • ** Includes some samples originating from before the covid-19 epidemic, and some during the epidemic, as further stratification was not possible.