Skip to main content
. 2021 Dec 14;4(12):e2137257. doi: 10.1001/jamanetworkopen.2021.37257

Table. Characteristics of the Studies Included for Meta-analysis.

Source Country Study design Time of publication Population group No. tested individuals No. confirmed individuals No. asymptomatic infections Quality
Abdelmoniem et al22 Egypt Cross-sectional January 2020 Health care workers or in-hospital patients 203 29 29 Low
Abeysuriya et al23 UK Cross-sectional September 2020 Pregnant women 180 7 6 Low
Akbarialiabad et al24 Iran Cross-sectional September 2020 Health care workers or in-hospital patients 1805 86 19 Low
Al-Qahtani et al25 Kingdom of Bahrain Cohort November 2020 Air or cruise travelers 2714 188 116 High
Al-Shamsi et al26 United Arab Emirates Cohort November 2020 Health care workers or in-hospital patients 109 32 6 Low
Arnold et al27 US Cross-sectional January 2021 Health care workers or/in-hospital patients 2882 103 38 Moderate
Arons et al12 US Cross-sectional April 2020 Nursing home residents or staff 76 48 27 Moderate
Aslam et al28 US Cohort January 2020 Health care workers or in-hospital patients 11 622 69 42 Low
Bayle et al29 France Cross-sectional January 2021 Nursing home residents or staff 241 32 24 Moderate
Bender et al30 US Cohort September 2020 Pregnant women 318 8 8 Moderate
Bianco et al31 US Cross-sectional May 2020 Pregnant women 155 24 24 Low
Blain et al32 US Case series July 2020 Nursing home residents or staff 113 44 8 Moderate
Blitz et al33 US Cohort August 2020 Pregnant women 382 71 45 Low
Blumberg et al34 US Cohort October 2020 Health care workers or in-hospital patients 1198 7 6 Low
Bosworth et al35 UK Cross-sectional July 2020 Health care workers or in-hospital patients 1282 53 16 Moderate
Cao et al36 China Cross-sectional November 2020 Community residents 9 865 404 300 300 High
Carroll et al37 Ireland Cohort October 2020 Close contact 4586 310 209 Moderate
Cattelan et al38 Italy Cohort August 2020 Health care workers or in-hospital patients 7595 395 109 Low
Cloutier et al39 Canada Cross-sectional August 2020 Community residents 330 6 6 Low
Corcorran et al40 US Cohort August 2020 Health care workers or in-hospital patients 25 10 4 Low
Deng et al41 China Case series on transmission October 2020 Close contact 347 27 1 High
Dora et al42 US Cross-sectional May 2020 Nursing home residents or staff 235 27 18 Low
Duan et al43 China Cross-sectional September 2020 Health care workers or/in-hospital patients 4729 4 4 Moderate
Figueiredo et al44 Portugal Cohort October 2020 Pregnant women 184 11 9 Low
Goldfarb et al45 US Cross-sectional May 2020 Pregnant women 757 20 9 Moderate
Graham et al46 UK Cross-sectional September 2020 Nursing home residents or staff 464 129 54 Moderate
Grechukhina et al47 US Cohort November 2020 Pregnant women 1567 141 44 High
Gruskay et al48 US Cohort June 2020 Health care workers or in-hospital patients 99 12 7 Low
Han et al49 China Cross-sectional June 2020 Community residents 29 299 18 18 Low
Harada et al50 Japan Cohort December 2020 Health care workers or in-hospital patients 1259 79 33 Low
Hcini et al51 France Cohort February 2020 Pregnant women 507 137 103 Low
Hoxha et al52 Belgium Cross-sectional July 2020 Nursing home residents or staff 280 427 8325 6244 Moderate
Hung et al53 China Case series September 2020 Air or cruise travelers 215 9 6 High
Ibrahim et al54 Indonesia Case series August 2020 Health care workers or in-hospital patients 4617 582 55 Low
Kennelly et al55 Ireland Cohort September 2020 Nursing home residents or staff 2968 1105 290 Low
Kessler et al56 Germany Cross-sectional December 2020 Health care workers or in-hospital patients 689 1 1 Moderate
Kimball et al57 US Cross-sectional April 2020 Nursing home residents or staff 76 23 13 Moderate
Kirshblum et al58 US Cohort July 2020 Health care workers or in-hospital patients 103 12 12 Low
Krüger et al59 Germany Cohort January 2021 Health care workers or in-hospital patients 6940 27 7 Low
Kwon et al60 South Korea Cross-sectional July 2020 Health care workers or in-hospital patients 2087 42 6 Low
LaCourse et al61 US Cohort May 2020 Pregnant women 230 13 1 Low
Ladhani et al62 UK Cohort September 2020 Nursing home residents or staff 518 158 97 High
Lan et al63 US Cross-sectional November 2020 Community residents 104 21 16 Moderate
Lavezzo et al64 Italy Cross-sectional July 2020 Community residents 2812 73 29 Moderate
Livingston et al65 UK Cohort October 2020 Health care workers or in-hospital patients 344 131 16 Moderate
Lombardi et al66 Italy Cohort June 2020 Health care workers or in-hospital patients 1573 139 28 Low
Ly et al67 France Cross-sectional November 2020 Nursing home residents or staff 1691 226 46 Moderate
Lytras et al68 Greece Cross-sectional April 2020 Air or cruise travelers 783 40 35 Low
Maechler et al69 Germany Cross-sectional December 2020 Community residents 4333 333 14 High
Marossy et al70 UK Cross-sectional September 2020 Nursing home residents or staff 2455 160 115 Moderate
Marschner et al71 Germany Cross-sectional July 2020 Health care workers or in-hospital patients 139 1 1 Low
Martinez-Fierro et al72 Mexico Cross-sectional October 2020 Close contact 81 34 5 Low
Massarotti et al73 Italy Cross-sectional August 2020 Pregnant women 333 7 6 Low
Mattar et al74 Caribbean Cross-sectional December 2020 Close contact 686 35 18 Low
Menting et al75 Germany Cross-sectional January 2020 Health care workers or in-hospital patients 1185 11 2 Low
Migueres et al76 France Cross-sectional September 2020 Health care workers or in-hospital patients 123 44 17 Low
Milani et al77 Italy Cross-sectional June 2020 Community residents 197 21 21 Moderate
Nishiura et al78 Japan Cross-sectional May 2020 Air or cruise travelers 565 13 4 Low
Ochiai et al79 Japan Cross-sectional June 2020 Pregnant women 52 2 2 Low
Olalla et al80 Spain Cross-sectional August 2020 Health care workers or in-hospital patients 498 2 2 Low
Olmos et al81 Chile Cross-sectional January 2021 Health care workers or in-hospital patients 413 14 14 Low
Park et al82 South Korea Cross-sectional April 2020 Community residents 1143 97 8 High
Park et al83 Korea Cohort December 2020 Air or cruise travelers 39 30 4 Low
Patel et al84 United States Cohort June 2020 Nursing home residents or staff 126 35 14 Low
Pavli et al85 Greece Case series on transmission September 2020 Air or cruise travelers 891 5 2 High
Petersen et al86 United Kingdom Cross-sectional October 2020 Community residents 36 061 115 88 Moderate
Puckett et al87 United States Cohort December 2020 Health care workers or in-hospital patients 227 2 2 Low
Ralli et al88 Italy Cohort December 2020 Community residents 298 12 9 Low
Rashid-Abdi et al89 Sweden Cohort November 2020 Health care workers or in-hospital patients 131 21 1 Low
Ren et al90 China Cohort February 2021 Air or cruise travelers 19 398 384 3103 1749 High
Rincón et al91 Spain Cohort September 2020 Health care workers or in-hospital patients 192 36 14 Low
Roxby et al92 United States Cohort May 2020 Nursing home residents or staff 80 3 2 Low
Sacco et al93 France Cohort November 2020 Nursing home residents or staff 179 63 12 Low
Santos et al94 Portugal Cross-sectional December 2020 Health care workers or in-hospital patients 8037 211 47 Low
Scheier et al95 Switzerland Cross-sectional February 2021 Health care workers or in-hospital patients 2807 68 8 High
Shah et al96 US Case series July 2020 Health care workers or in-hospital patients 625 1 1 Low
Shi et al97 US Cohort October 2020 Nursing home residents or staff 389 146 66 Moderate
Singer et al98 US Case series October 2020 Health care workers or in-hospital patients 4751 18 10 High
Tang et al99 China Cross-sectional July 2020 Health care workers or in-hospital patients 1027 52 13 High
Tang et al100 US Cohort November 2020 Nursing home residents or staff 1970 752 424 High
Temkin et al101 Israel Cross-sectional October 2020 Health care workers or in-hospital patients 522 1 1 Low
Trahan et al102 Canada Cohort November 2020 Pregnant women 803 41 11 Low
Tsou et al103 China Case series November 2020 Community residents 17 935 100 10 Moderate
van Buul et al104 The Netherlands Cohort Decem ber 2020 Nursing home residents or staff 839 25 6 High
Varnell et al105 US Cohort January 2021 Health care workers or in-hospital patients 281 24 9 Moderate
Wadhwa et al106 US Cohort December 2020 Community residents 172 19 12 Moderate
Wi et al107 South Korea Case series July 2020 Community residents 17 400 111 25 High
Wood et al108 Indiana Cross-sectional August 2020 Community residents 511 1 1 Low
Yamahata et al109 Japan Cross-sectional May 2020 Air or cruise travelers 3711 696 410 Moderate
Yassa et al110 Turkey Cohort July 2020 Pregnant women 296 23 12 Low
Yau et al111 Canada Cohort July 2020 Health care workers or in-hospital patients 330 22 12 Low
Yousaf et al112 US Cohort July 2020 Close contact 195 47 6 Low
Zhang et al113 China Case series on transmission April 2020 Close contact 8437 25 3 High
Zhang et al114 China Cohort September 2020 Health care workers or in-hospital patients 8553 235 21 Low
Zhao et al115 China Cohort August 2020 Health care workers or in-hospital patients 1060 160 38 Low