# External validation of HAS model in predicting mortality after emergency laparotomy: a retrospective cohort study

## TL;DR

This study validates a model called HAS for predicting death after emergency abdominal surgery, finding it performs well, especially in older patients.

## Contribution

The study provides external validation of the HAS model for mortality prediction in emergency laparotomy patients.

## Key findings

- The HAS model had an AUC of 0.90 for predicting 30-day mortality after emergency laparotomy.
- The HAS model outperformed the NELA score in predicting mortality for patients aged 50 and older.
- The performance difference between HAS and NELA was statistically significant in older age subgroups.

## Abstract

We aimed to externally validate the performance of the HAS model (Hajibandeh Index, American Society of Anaesthesiologists status, and sarcopenia) in predicting mortality after emergency laparotomy. We also aimed to compare the HAS model with the Parsimonious NELA (National Emergency Laparotomy Audit) risk score.

In this retrospective cohort study, we included adult patients who underwent emergency laparotomy between January 2022 and June 2023. The performance of the HAS score and the NELA score in predicting 30-day mortality was compared using receiver operating characteristic (ROC) curve analysis. We performed subgroup analysis for the following age groups: age ≥50, age ≥60, age ≥70, and age ≥80 years.

We included 117 patients in this study. ROC curve analysis showed that area under the curve (AUC) of the HAS score for 30-day mortality was 0.90 (95% CI 0.83–0.95). Although the AUC of HAS score was higher than the AUC of NELA score for all patients, this was not statistically significant (0.90 vs 0.80, p=0.097). AUC of the HAS score was superior to NELA score in patients aged ≥50 (0.89 vs 0.75, p=0.040), patients aged ≥60 (0.87 vs 0.69, p=0.020), patients aged ≥70 (0.85 vs 0.67, p=0.030), and patients aged ≥80 (0.90 vs 0.66, p<0.001).

The results of the current study support the external validity of the HAS model in predicting 30-day mortality after emergency laparotomy. Prospective studies with larger sample size are required.