Are we taking a risk with risk assessment tools? Evaluating the relationship between NSQIP and the ACS risk calculator in colorectal surgery

To evaluate the relationship between the ACS Risk Calculator and NSQIP expected outcomes in elective colorectal resections. The 2015 NSQIP morbidity report for elective colorectal procedures at a single institution was evaluated. Risk Calculator (RC) reports were completed for predicted risk. Correlation coefficients were calculated for the general relationship between the tools for complications. Receiver operator characteristic (ROC) curves compared the predictive accuracy of the tools to actual outcome measures of any complication, serious complications, readmissions, unplanned return to the operating room, and mortality. There was high correlation between NSQIP and the RC for any complication, but low correlation for serious complications. Predictive accuracy of both tools for identifying actual occurrences was poor, with area under the ROC