Comparison of risk adjustment methodologies in surgical quality improvement.

Background: All hospitals are required to perform quality assurance activities. Many risk adjustment methodologies have been developed, and many medical centers use 1 or more than 1 risk adjustment program in an attempt to characterize their outcomes better rather than simply assessing unadjusted outcome statistics. The University HealthSystem Consortium (UHC) and American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) both produce risk-adjusted outcome data.