Validation study of the ACS NSQIP surgical risk calculator for two procedures in Japan.

INTRODUCTION:The ACS NSQIP Surgical Risk Calculator (SRC) assesses risk to support goal-concordant care. While it accurately predicts US outcomes, its performance internationally is unknown. This study evaluates SRC accuracy in predicting mortality following low anterior resection (LAR) and pancreaticoduodenectomy (PD) in NSQIP patients and accuracy retention when applied to native Japanese patients (National Clinical Database, NCD). METHODS:NSQIP (41,260 LAR; 15,114 PD) and NCD cases (61,220 LAR; 27,901 PD) from 2015 to 2017 were processed through the SRC mortality model. Country-specific calibration and discrimination were assessed with and without an intercept correction applied to the Japanese data. RESULTS:The SRC exhibited acceptable calibration for LAR and PD when applied to NSQIP data but miscalibration for NCD data. A simple correction to the model intercept, motivated by lower mortality rates in the Japanese data, successfully remediated the miscalibration. CONCLUSIONS:The SRC may inaccurately predict surgical risk when applied to the native Japanese population. An intercept correction method is suggested when miscalibration is encountered; it is simple to implement and may permit effective international use of the SRC.