Comparison between P-POSSUM and NELA risk score for patients undergoing emergency laparotomy in Egyptian patients.

BACKGROUND AND AIMS: The Portsmouth-Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (P-POSSUM) is one of the scores that is used most frequently for determining the likelihood of mortality in patients undergoing emergency laparotomy. National Emergency Laparotomy Audit (NELA) presents a novel and validated score. Therefore, we aimed to compare the performance of the NELA and P-POSSUM mortality risk scores in predicting 30-day and 90-day mortality in patients undergoing emergency laparotomy.

METHODS: Between August 2020 and October 2022, this cohort study was undertaken at Menoufia University Hospital. We compared the P-POSSUM, preoperative NELA, and postoperative NELA scores in patients undergoing emergency laparotomy. All variables needed to calculate the used scores were collected. The outcomes included the death rates at 30 and 90 days. By calculating the area under the curve (AUC) for every mortality instrument, the discrimination of the various methods was evaluated and compared.

RESULTS: Data from 670 patients were included. The observed risk of 30-day and 90-day mortality was 10.3% (69/670) and 13.13% (88/670), respectively. Concerning 30-day mortality, the AUC was 0.774 for the preoperative NELA score, 0.763 for the preoperative P-POSSUM score, and 0.780 for the postoperative NELA score. Regarding 90-day mortality, the AUCs for the preoperative NELA score, preoperative P-POSSUM score, and postoperative NELA score were 0.649 (0.581-0.717), 0.782 (0.737-0.828), and 0.663 (0.608-0.718), respectively. There was noticeable difference in the three models' capacity for discrimination, according to pairwise comparisons.

CONCLUSIONS: The probability of 30-day and 90-day death across the entire population was underestimated by the NELA and P-POSSUM scores. There was discernible difference in predictive performance between the two scores.