Validation of the American College of Surgeons National Surgical Quality Improvement Program risk predictor in an Australian general surgical cohort

BACKGROUND: The National Surgical Quality Improvement Program (NSQIP) Surgical Risk Calculator from the American College of Surgeons is a widely available tool for peri-operative risk prediction. This study investigates its predictive performance in an Australian setting. METHODS: A single-centre retrospective external validation study was conducted at a tertiary referral centre in New South Wales, Australia. Data from a general surgical cohort in a 2-year period from 2020 to 2021 was collected from the NSQIP database and entered into the NSQIP calculator. The predictive performance of the calculator was analysed across the standard 14 NSQIP postoperative outcome measures at 30 days. RESULTS: There were 2121 patient records analysed using tests of accuracy and in the discrimination and calibration domains. The overall predictive performance of the NSQIP calculator was reasonable. There was greater accuracy at lower-risk predictions. At higher-risk predictions, Readmission, Death, and Discharge to Nursing or Rehab Facility, and Length of Stay were overestimated, whilst other outcomes were underestimated. CONCLUSION: This study demonstrates reasonable overall performance of the NSQIP calculator in the context of this cohort and provides data to support the need for locally adapted and validated risk prediction tools for use by Australian perioperative physicians.