Prospective validation of the ICH Score for 12-month functional outcome

Abstract

Background: The ICH Score is a commonly used clinical grading scale for outcome after acute intracerebral hemorrhage (ICH) and has been validated for 30-day mortality, but not long-term functional outcome. The goals of this study were to assess whether the ICH Score accurately stratifies patients with regard to 12-month functional outcome and to further delineate the pace of recovery of patients during the first year post-ICH.

Methods: We performed a prospective observational cohort study of all patients with acute ICH admitted to the emergency departments of San Francisco General Hospital and UCSF Medical Center from June 1, 2001, through May 31, 2004. Components of the ICH Score (admission Glasgow Coma Scale score, initial hematoma volume, presence of intraventricular hemorrhage, infratentorial ICH origin, and age) were recorded along with other clinical characteristics. Patients were then assessed with the modified Rankin Scale (mRS) at hospital discharge, 30 days, and 3, 6, and 12 months post-ICH.

Results: Of 243 patients, 95 (39%) died during initial acute hospitalization. The ICH Score accurately stratified patients with regard to 12-month functional outcome for various dichotomous cutpoints along the mRS (p < 0.05). Many patients continued to improve across the first year, with a small number of patients becoming disabled or dying due to late events unrelated to the initial ICH.

Conclusions: The ICH Score is a valid clinical grading scale for long-term functional outcome after acute intracerebral hemorrhage (ICH). Many ICH patients improve after hospital discharge and this improvement may continue even after 6 months post-ICH.

Figure 1 Favorable 12-month outcome based on various dichotomized cutpoints Distribution of modified Rankin Scale (mRS) scores at 12 months after intracerebral hemorrhage (ICH) with favorable outcome defined using various dichotomized cutpoints. The Y-axis indicates the percentage of patients who achieved the indicated outcome. (A) considers a favorable outcome as a 12-month mRS of ≤1 (able to carry out all usual duties or activities); (B) as an mRS of ≤2 (slight disability); (C) as an mRS of ≤3 (moderate disability but ambulatory); (D) as an mRS of ≤4 (moderate to severe disability; nonambulatory). For each outcome cutpoint, rising ICH Scores are associated with lower likelihood of favorable outcome (p < 0.05, test for trend). Note that one patient (out of 12) with an ICH Score of 5 achieved a 12-month mRS of 2 after evacuation of a cerebellar hematoma.

Figure 2 Change in modified Rankin Scale (mRS) score during first year after intracerebral hemorrhage (ICH) (A) Patients who remained the same or improved their mRS score across various timepoints assessed during the first year post-ICH. While most patients remained the same, substantial numbers of patients improved throughout the year. (B) Patients who worsened their mRS during the first year post-ICH. Most of those who worsened functionally did so by one step on the mRS. However, several patients developed new unrelated events after 3 months which led to death. Arrow thickness is used to represent the proportion of patients with a specific mRS score who change or stay the same to the next timepoint. Arrow color is used to depict change in mRS score from one timepoint to next (no change = gray, 1-point change = blue, 2 = red, 3 = green, 4 = black, 5 = purple).