Multivariable models of the probability of RBCT herds experiencing a confirmed bTB breakdown during the period under study.

Odds ratios (OR) are quoted with their corresponding 95% confidence interval, and for covariates correspond to the change in the risk of a confirmed bTB breakdown following a doubling of the value of the covariate.
The --- means that an individual predictor was not significant and removed from the model, while NA corresponds to variables that were not included following the screening process.
1Models are adjusted for herd size, herd type and farm area (model A); herd size, herd type, farm area and bTB historic incidence within the trial area (model B).
2Relate to the badgers culled during the initial proactive cull.
3Relate to the badger setts identified during the initial survey.
4Relate to herds tested for bTB during the one year prior to the start of the initial proactive cull.