Final multivariable Cox regression model for time to infection of premises in the largest cluster (n = 3153), northwest of Sydney, during the 2007 equine influenza outbreak in Australia.

Number of events = 1727; Log likelihood = −12,847.4; df = 25; P<0.001; R2 = 25.8%.
aP-values derived from Likelihood ratio tests (LRT).
bTime-changing covariate, time-lagged 3 or 5 days as noted.
cMaximum daily wind speed (‘directed’) based on wind only from within 45° arcs centred on the direction of the three nearest infected premises assuming that premises were infectious for 14 days and one of the three nearest infective premises was the source of infection.