PT  - JOURNAL ARTICLE
AU  - Conor McAloon
AU  - Áine Collins
AU  - Kevin Hunt
AU  - Ann Barber
AU  - Andrew W Byrne
AU  - Francis Butler
AU  - Miriam Casey
AU  - John Griffin
AU  - Elizabeth Lane
AU  - David McEvoy
AU  - Patrick Wall
AU  - Martin Green
AU  - Luke O'Grady
AU  - Simon J More
TI  - Incubation period of COVID-19: a rapid systematic review and meta-analysis of observational research
AID  - 10.1136/bmjopen-2020-039652
DP  - 2020 Aug 01
TA  - BMJ Open
PG  - e039652
VI  - 10
IP  - 8
4099  - http://bmjopen.bmj.com/content/10/8/e039652.short
4100  - http://bmjopen.bmj.com/content/10/8/e039652.full
SO  - BMJ Open2020 Aug 01; 10
AB  - Objectives The aim of this study was to conduct a rapid systematic review and meta-analysis of estimates of the incubation period of COVID-19.Design Rapid systematic review and meta-analysis of observational research.Setting International studies on incubation period of COVID-19.Participants Searches were carried out in PubMed, Google Scholar, Embase, Cochrane Library as well as the preprint servers MedRxiv and BioRxiv. Studies were selected for meta-analysis if they reported either the parameters and CIs of the distributions fit to the data, or sufficient information to facilitate calculation of those values. After initial eligibility screening, 24 studies were selected for initial review, nine of these were shortlisted for meta-analysis. Final estimates are from meta-analysis of eight studies.Primary outcome measures Parameters of a lognormal distribution of incubation periods.Results The incubation period distribution may be modelled with a lognormal distribution with pooled mu and sigma parameters (95% CIs) of 1.63 (95% CI 1.51 to 1.75) and 0.50 (95% CI 0.46 to 0.55), respectively. The corresponding mean (95% CIs) was 5.8 (95% CI 5.0 to 6.7) days. It should be noted that uncertainty increases towards the tail of the distribution: the pooled parameter estimates (95% CIs) resulted in a median incubation period of 5.1 (95% CI 4.5 to 5.8) days, whereas the 95th percentile was 11.7 (95% CI 9.7 to 14.2) days.Conclusions The choice of which parameter values are adopted will depend on how the information is used, the associated risks and the perceived consequences of decisions to be taken. These recommendations will need to be revisited once further relevant information becomes available. Accordingly, we present an R Shiny app that facilitates updating these estimates as new data become available.