Anzai 2020.

Study characteristics
Study design	Mathematical modelling study  Description: counterfactual projection model based on Poisson process The model assumes a Poisson process determining exported cases to destination countries from China and the probability of a major epidemic in destination countries based on a negative binomial distribution of generated secondary cases. This counterfactual projection is compared to observed exported cases. Model allows for untraced cases and imperfect contact tracing.
Disease	COVID‐19
Travel‐related control measure(s)	Multiple measures Complete border closure Travel restrictions  Quarantine of travellers Entry screening for all incoming travellers Date of implementation: January 23 2020
Country implementing the measure(s)	Country protected by the measure: n.r./Japan for outcome 2 Country restricted by the measure: China
Outcome(s)	Cases avoided due to the measure Outcome 1: number of exported out cases from China Follow‐up: 28 January – 6 February 2020 Shift in epidemic development Outcome 2: absolute risk reduction in the probability of major epidemic Follow‐up: 28 January – 6 February 2020 Shift in epidemic development Outcome 3: time to a major epidemic Follow‐up: 28 January 28 – 6 February 2020
Notes	COI: “The authors declare no conflicts of interest.” Funding: “H.N. received funding from the Japan Agency for Medical Research and Development (AMED) [grant number: JP18fk0108050]; the Japan Society for the Promotion of Science (JSPS) KAKENHI [grant numbers, H.N.: 17H04701, 17H05808, 18H04895 and 19H01074; R.K.: 18J21587; AS.: 19K24159], the Inamori Foundation, and the Japan Science and Technology Agency (JST) CREST program [grant number: JPMJCR1413]. SMJ and NML receive graduate study scholarships from the Ministry of Education, Culture, Sports, Science and Technology, Japan.”