Validation of the emergency surgery score (ESS) in a UK patient population and comparison with NELA scoring: a retrospective multicentre cohort study

Abstract

Introduction Accurate risk scoring in emergency general surgery (EGS) is vital for consent and resource allocation. The emergency surgery score (ESS) has been validated as a reliable preoperative predictor of postoperative outcomes in EGS but has been studied only in the US population. Our primary aim was to perform an external validation study of the ESS in a UK population. Our secondary aim was to compare the accuracy of ESS and National Emergency Laparotomy Audit (NELA) scores. Methods We conducted an observational cohort study of adult patients undergoing emergency laparotomy over three years in two UK centres. ESS was calculated retrospectively. NELA scores and all other variables were obtained from the prospectively collected Emergency Laparotomy and Laparoscopic Scottish Audit (ELLSA) database. The primary and secondary outcomes were 30-day mortality and postoperative intensive care unit (ICU) admission, respectively. Results A total of 609 patients were included. Median age was 65 years, 52.7% were female, the overall mortality was 9.9% and 23.8% were admitted to ICU. Both ESS and NELA were equally accurate in predicting 30-day mortality (c-statistic=0.78 (95% confidence interval (CI), 0.71–0.85) for ESS and c-statistic=0.83 (95% CI, 0.77–0.88) for NELA, p=0.196) and predicting postoperative ICU admission (c-statistic=0.76 (95% CI, 0.71–0.81) for ESS and 0.80 (95% CI, 0.76–0.85) for NELA, p=0.092). Conclusions In the UK population, ESS and NELA both predict 30-day mortality and ICU admission with no statistically significant difference but with higher c-statistics for NELA score. Both scores have certain advantages, with ESS being validated for a wider range of outcomes.