Updating threshold-based identification of hospitalists in 2012 Medicare pay data.

In the absence of a unique identifier, it is difficult to assess the number of practicing hospitalists. We use a variety of thresholds of billing activity to identify hospitalists in a dataset of publicly released 2012 Medicare physician pay data. Our study updates previous estimates of the number of hospitalists practicing nationwide in 2012 and suggests the field continues to grow. This research also highlights a need for a more precise system of identifying hospitalists.