Table 1

Study size and extracted data for the lognormal mu and sigma parameters from the nine studies that were used for meta-analysis

AuthornPublication status
1 July 2020
LocationObservation periodMean
(95th) percentile
Lognormal parameters used in meta-analysis
Backer et al3488PRChinese and international—travellers from Wuhan20–28 January6.411.11.7960.0770.3490.045
Lauer et al27181PRChinese and international - travellers from known affected areas4 January to
24 February
Li et al2810PREarly cases in Wuhan1 December to
31 January
Bi et al26183PRShenzhen—travellers from Wuhan14 January to
12 February
Jiang et al3240PPLocation unclear14 December to
8 February
Linton et al29158PRCases external to WuhanStart of epidemic until 31 January5.610.8**1.6110.0700.4720.048
Zhang et al3149PRChina—provinces other than HubeiStart of epidemic until 27 February5.210.5**1.5400.0920.4700.072
Ma et al30587PPMultiple countries including ChinaNot specified7.4171.8570.0240.5470.023
Leung3561†PRChina—provinces other than Hubei10 January to
12 February
  • *Median, **95th percentile

  • †Inferred from data reported.

  • PP, preprint, not peer reviewed; PR, published, peer reviewed.