Reliability of the intracerebral hemorrhage score for predicting outcome in patients with intracerebral hemorrhage using oral anticoagulants

Background and purpose The intracerebral hemorrhage (ICH) score is the most widely used and validated prognostic model for estimating 30-day mortality in ICH. However, the score was developed and validated in an ICH population probably not using oral anticoagulants (OACs). The aim of this study was to determine the performance of the ICH score for predicting the 30-day mortality rate in the full range of ICH scores in patients using OACs. Methods Data from admitted patients with ICH were collected retrospectively in two Dutch comprehensive stroke centers. The validity of the ICH score was evaluated by assessing both discrimination and calibration in OAC and OAC-naive patient groups. Results A total of 1752 patients were included of which 462 (26%) patients were on OAC. The 30-day mortality was 54% for the OAC cohort and 34% for the OAC-naive cohort. The 30-day mortality was higher in the OAC cohort for ICH score 1 (33% vs. 12.5%; odds ratio, 3.4; 95% confidence intervals, 1.1-10.4) and ICH score 2 (53% vs. 26%; odds ratio, 3.2; 95% confidence intervals, 1.2-8.2) compared with the predicted mortality rate of the original ICH score. Overall, the discriminative ability of the ICH score was equally good in both cohorts (area under the curve 0.83 vs. 0.87, respectively). Conclusions The ICH score underestimated the 30-day mortality rate for lower ICH scores in OAC-ICH. When estimating the prognosis of ICH in patients using OAC, this underestimation of mortality must be taken into account.