Comparative external validation of ICH prognostic scores for discharge outcomes in the RES-Q multinational quality registry.

backgroundPrognostic scores are routinely applied after spontaneous intracerebral haemorrhage (ICH) to inform clinical decision-making and stratify risk; however, direct comparative validation in contemporary, multinational real-world cohorts remains scarce.

aimsTo compare the discriminative performance of the ICH Score, max-ICH and ICH Functional Outcome Score (ICH-FOS) for discharge outcomes after spontaneous intracerebral haemorrhage in a large contemporary multinational cohort from the International Registry of Stroke Care Quality (RES-Q).

methodsWe analysed consecutive adults with spontaneous ICH recorded in RES-Q between September 2024 and April 2025. Discharge outcomes were defined according to the modified Rankin Scale (mRS): mortality (mRS = 6), unfavourable functional outcome (mRS ≥ 4) and composite poor outcome (mRS 5-6). Discrimination was assessed using receiver operating characteristic curves and area under the curves (AUCs) with 95% confidence intervals. Areas under the curve were compared in the same complete-case cohort using global tests and pairwise DeLong contrasts. Score distributions were characterised descriptively to explore differences in granularity.

resultsThe complete-case cohort comprised 8450 patients from 56 countries. Median age was 63 (20) years, and 62% were male. Median National Institutes of Health Stroke Scale was 11 (12), Glasgow Coma Scale 14 (4) and median haematoma volume 16 (27) mL. Supratentorial ICH occurred in 82.1%, intraventricular haemorrhage in 31.5% and pre-admission oral anticoagulant use in 4.5%. Discharge mortality was 15.1% and favourable outcome (mRS 0-3) 56.6%. Discrimination was good for mortality (AUC 0.82 [0.81-0.83] for ICH Score, 0.81 [0.79-0.82] for max-ICH, 0.84 [0.83-0.86] for ICH-FOS; global P < .0001). For unfavourable outcome (mRS ≥ 4), AUCs were 0.77 (0.76-0.78), 0.81 (0.81-0.82) and 0.84 (0.83-0.85), respectively (P < .0001). For composite poor outcome (mRS 5-6), AUCs were 0.83 (0.82-0.84), 0.84 (0.83-0.85) and 0.87 (0.86-0.88) (P < .0001).

conclusionsIn this large, contemporary, multinational registry cohort, all 3 prognostic scores demonstrated acceptable-to-excellent discriminative ability for discharge outcomes following spontaneous ICH. ICH Functional Outcome Score consistently achieved the highest discriminative performance across all endpoints, whereas max-ICH provided a pragmatic and robust alternative based on routinely available clinical variables.