Table 1

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

CharacteristicsELISALFIACLIAOther*
No of studiesNo of participantsNo of studiesNo of participantsNo of studiesNo of participantsNo of studiesNo of participants
Total15254817†18571337503140
Peer reviewed:        
 Yes81339785973090116
 No7120911104766602123
Geographical location:        
 China1115728911123635157
 Denmark1112162- 116
 Italy--33011125--
 Japan--1160----
 Spain--1100----
 Sweden--1153----
 United Kingdom190190--  
 United States2774180--167
 Germany--149----
Clinical setting:        
 Inpatient only11130791508113119116
 Outpatient-49149----
 Inpatient and outpatient21703349  --
 Not reported21041577826312124
Study design:        
 Case-control15254812894113410283
 Cohort0-610121‡56157
Time from symptom onset to index test§:        
  First week61727190541--
 Second week723991955105--
 Third week or later515992155328--
Accuracy at level of patient or sample:        
 Patient6149510140783080273
 Samples††9211581252515991132
Population for estimating specificity‡‡:        
 None2-3-3-1-
 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.