Table 4

Correlation of population variables and epidemic statistics as seen and predicted by the model.

Full dataset

Epidemic statistic

Population variable

Correlation observed in real data^a

Correlation predicted by the model^a

r

P

r

P

Worldwide

Peak week

Air traffic to/from North America

-0.30

0.042

-0.30

0.044

Peak week

Longitude^b

0.27

0.071

0.42

0.003

Peak week

Latitude^b

-0.15

0.317

0.02

0.882

Peak week

Vaccine uptake

-0.37

0.069

-0.38

0.060

Attack rate reduction, %

Vaccine uptake

0.73

< 0.001

European countries only

Peak week

Intra-EU air traffic

-0.15

0.391

-0.48

0.003

Peak week

Air traffic to/from North America

-0.26

0.151

-0.37

0.003

Peak week

Longitude^b

0.54

< 0.001

0.74

< 0.001

Peak week

Latitude^b

-0.32

0.07

-0.23

0.178

Peak week

Vaccine uptake

-0.29

0.204

-0.28

0.212

Attack rate reduction, %

Vaccine uptake

0.69

< 0.001

^aValues of the Pearson's correlation coefficient, r, along with the corresponding P value, were measured between the epidemic statistics and the population variables of the countries appearing in Figure 5.

^bLongitude and latitude are those of the capital city of the country.

Tizzoni et al. BMC Medicine 2012 10:165   doi:10.1186/1741-7015-10-165