# External validation of the CRASS score for predicting good neurological outcome in out-of-hospital cardiac arrest: analysis from cardiac-origin and non-cardiac origin cohorts

## TL;DR

This study validates a scoring system for predicting neurological outcomes in cardiac arrest patients, showing it works better for heart-related cases than non-heart-related ones.

## Contribution

The study externally validates the CRASS score in Asian OHCA patients, highlighting its differential performance in cardiac versus noncardiac cohorts.

## Key findings

- CRASS score had an AUROC of 0.770 in cardiac-origin OHCA patients.
- CRASS score predicted poor outcomes better in noncardiac-origin cases with an AUROC of 0.729.
- Optimal cut-off values differed between cardiac and noncardiac groups, guiding treatment decisions.

## Abstract

This study aimed to externally validate the CaRdiac Arrest Survival Score (CRASS) for predicting good neurological outcomes in Asian patients with out-of-hospital cardiac arrest (OHCA), focusing on cardiac-origin and noncardiac-origin cohorts, respectively.

This multicenter retrospective cohort study, conducted from January 2016 to December 2023 across three hospitals in Taiwan, included patients with OHCA with resuscitation attempts, and excluded those with trauma-related arrests, pediatric cases, or missing data. The CRASS score was calculated for each patient according to the clinical variables at presentation. The outcome involves a good neurological outcome (Cerebral Performance Category (CPC) 1 or 2) at hospital discharge. Predictive performance was evaluated using the area under the receiver operating characteristic curve (AUROC), calibration plots, and other performance metrics, including sensitivity, specificity, and positive and negative predictive values.

This study analyzed 1,311 patients with OHCA (667 cardiac-origin and 644 noncardiac-origin). The AUROC for predicting good neurological outcomes was 0.770 (95% confidence interval [CI]: 0.733–0.807) in the cardiac-origin cohort compared with 0.729 (95% CI: 0.661–0.796) in the noncardiac-origin cohort. The CRASS score exhibited better predictive performance in patients with cardiac origin, with an optimal cut-off value of 1.45, thereby supporting more aggressive treatment. The score in patients with noncardiac origin was more effective in predicting poor neurological outcomes, with an optimal cut-off value of − 1.47, favoring life support withdrawal.

The CRASS score is effective for predicting good neurological outcomes in patients with cardiac-origin OHCA but is more suited to guiding treatment withdrawal in noncardiac-origin cases.

Not applicable.

The online version contains supplementary material available at 10.1186/s12873-026-01472-4.