Five-Year Functional Outcomes Among Patients Surviving Aneurysmal Subarachnoid Hemorrhage

Abstract

Importance: Longitudinal changes in functional levels can provide valuable information about disability. However, longitudinal outcomes in aneurysmal subarachnoid hemorrhage (aSAH) have not been well reported, which could provide insight into appropriate management and information for patients experiencing disability.

Objective: To investigate the 5-year prognosis and functional outcomes of patients with aSAH.

Design, setting, and participants: This retrospective cohort study used data of patients with aSAH from the Korean Stroke Cohort for Functioning and Rehabilitation study up to 5 years after onset. Data were collected from August 2012 through May 2015 in 9 different hospitals in Korea. Data were analyzed from September 2023 through January 2024.

Exposure: Patients with aSAH surviving at least 7 days after onset.

Main outcomes and measures: Assessments were performed serially from 7 days to 5 years after onset. Prognosis, measured by the modified Rankin scale (mRS) in terms of positive outcome (mRS score of 0 or 1), and mortality were analyzed. In addition, sequential functional outcomes were assessed using the Functional Independence Measure (FIM) in survivors of aSAH at 5 years after onset. Multiple imputation method was used to handle missing data. Wilcoxon signed-rank test and paired t test were used to analyze differences in functional measurements between each follow-up period. Additionally, a generalized mixed-effects model was used to analyze the longitudinal trajectory of the FIM.

Results: A total of 338 patients with aSAH (mean [SD] age, 56.3 [13.0] years; 207 female [61.2%]) were included. Among survivors of aSAH at 7 days, the 5-year mortality rate was 8.3% (28 participants). The distribution of mRS significantly improved until 4 years and then plateaued, with 180 (53.3%) and 77 (22.8%) patients reporting an mRS score of 0 and 1, respectively. FIM showed a significant improvement up to 4 years (mean [SD] score, 118.9 [18.7]) and then plateaued.

Conclusions and relevance: In this cohort study, the functional outcomes in patients with aSAH continued to improve up to 4 years after onset, with the majority of participants showing favorable outcomes without significant disability, suggesting that proper long-term assessment is needed and appropriate management should be emphasized to maximize potential outcomes of patients with aSAH.

Figure 1.. Inclusion Flowchart

Figure 2.. Proportion of Patients Stratified by Modified Rankin Scale (mRS) Over Time

An mRS score of 0 indicated no disability, a score of 1 to 3 indicated mild to moderate disability, a score of 4 to 5 indicated severe disability, and a score of 6 indicated mortality. Group 1 consisted of patients with an mRS score of 0 to 3 at 7 days after onset, while group 2 consisted of patients with an mRS score of 4 or 5 at 7 days after onset. P values compared between each time point using the Wilcoxon signed-rank test with Bonferroni correction. aSAH indicates aneurysmal subarachnoid hemorrhage. ^aP < .05. ^bP < .001.

Figure 3.. Recovery Patterns of the Functional Independence Measure (FIM)

FIM scores range from 18 to 126, with 18 indicating total dependence and 126 indicating total independence in activities of daily living. Group 1 consisted of patients with a modified Rankin scale score of 0 to 3 (mild to moderate disability) at 7 days after onset, while group 2 consisted of patients with an mRS score of 4 or 5 (severe disability) at 7 days after onset. aSAH indicates aneurysmal subarachnoid hemorrhage. ^aP < .05. ^bP < .001, compared between each time point using paired t test with Bonferroni correction.