Outcomes reported by the Vascular Quality Initiative and the National Surgical Quality Improvement Program are not comparable

VQI and NSQIP demonstrate substantial concordance for most preoperative variables and poor concordance for most postoperative variables, even at identical collection periods. This discordance is a result of differences in data collection methods and variable definitions. On the basis of these findings, VQI and NSQIP data sets cannot be used to directly compare risk-adjusted patient outcomes between institutions.