In the article that appeared on pages E57-E64 of the January/February 2015 issue, the first sentence of the second paragraph of the Methods section should have read "the full negative binomial regression model took the form of:

Equation (Uncited)

where y is the estimated number of incident TBIs in a given month, x₁ is the number of amputations, and x₂ is the estimated number of deployed active component military personnel (in thousands).

The authors regret the error.

Reference