Off the shelf or recalibrate? customizing a risk index for assessing mortality.

Background: Public "report cards" for cardiac surgery have been freely available from a variety of sources. These risk-adjusted indices serve as a means of benchmarking outcomes performances, allowing comparisons of outcomes between surgical programs, and quantifying quality improvement programs. We examined two alternative strategies for using previously developed risk-adjusted mortality models in a community hospital: (1) using the model "off the shelf" (OTS) and (2) recalibrating the existing model (RM) to fit the institution-specific population.