Accuracy of the ACS NSQIP surgical risk calculator in predicting postoperative outcomes in colorectal surgery in Saudi Arabia

Background: Accurate perioperative risk assessment is essential for surgical decision-making and predicting patient outcomes. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator (SRC) is widely used for estimating postoperative complications. However, its accuracy across different populations remains uncertain. Objectives: This study aimed to externally validate the ACS NSQIP SRC in Saudi Arabia, focusing on colorectal cancer (CRC) patients at King Abdulaziz Medical City, Riyadh. It assessed the accuracy of the SRC in predicting 30-day postoperative complications, particularly cardiac events, mortality, and surgical site infections. Additionally, the study evaluated the SRC’s role in improving informed consent and surgical decision-making. Methods: A retrospective review was conducted on CRC patients who underwent surgery between 2016 and 2018. Demographic and clinical data, including 20 ACS NSQIP SRC parameters, were collected. Predicted risks were calculated using the SRC and compared to actual outcomes, including surgical site infections, myocardial infarction, pneumonia, and mortality. Predictive accuracy was assessed using the Brier score and the area under the receiver operating characteristic curve (AUC). Results: Among 109 patients, 40.37% experienced complications, with serious complications in 18.35%. The SRC demonstrated high accuracy for cardiac complications (AUC = 0.8, Brier score = 0.01) and moderate accuracy for pneumonia (AUC = 0.71, Brier score = 0.02). Conclusions: The ACS NSQIP SRC accurately predicted key postoperative complications, supporting its use in Saudi surgical practice. Further research is needed to explore its applicability across other specialties.