The Emergency Surgery Score (ESS) is an accurate mortality risk calculator for emergency general surgery (EGS). We sought to assess whether ESS can accurately predict 30-day morbidity, mortality, and requirement for postoperative Intensive Care Unit (ICU) care in patients with missing data variables.

All EGS patients with one or more missing ESS variables in the 2007–2015 ACS-NSQIP database were included. ESS was calculated assuming that a missing variable is normal (i.e. no additional ESS points). The correlation between ESS and morbidity, mortality, and postoperative ICU level of care was assessed using the c-statistics methodology.

Out of a total of 4,456,809 patients, 359,849 were EGS, and of those 256,278 (71.2%) patients had at least one ESS variable missing. ESS correlated extremely well with mortality (c-statistic = 0.94) and postoperative requirement of ICU care (c-statistic = 0.91) and well with morbidity (c-statistic = 0.77).

ESS performs well in predicting outcomes in EGS patients even when one or more data elements are missing and remains a useful bedside tool for counseling EGS patients and for benchmarking the quality of EGS care.