Capability of adding an exogenous covariate to forecast.

The number of confirmed Emergency Department (ED) influenza cases compared to the base 3rd order Negative Binomial Generalized Autoregressive Poisson (GARMA) model. Δ indicates the change of the indicated variable between the prior and current week. Forecast Global Deviance indicates the sum of each forecast global deviance for all 7 leave-one-out validation models. Forecast Confidence indicates the average of confidences from all 7 leave-one-out validation models. Forecast confidence is the percentage of forecast values, during an influenza peak, that are within seven influenza cases of the actual data.