Long-term functional outcomes among patients surviving aneurysmal subarachnoid hemorrhage: The KOSCO study

Background and objectives: Aneurysmal subarachnoid hemorrhage (aSAH) remains a significant global health concern, and therefore, understanding their functional outcomes is essential. The aim of this study was to investigate the 1-year functional outcomes of patients with aSAH. Methods: We retrospectively analyzed data of patients with aSAH from the Korean Stroke Cohort for Functioning and Rehabilitation study, up to 1 year post-onset. The cohort data were collected twice. The first data was collected from August 2012 through May 2015, and the second data was collected from January to December in 2020, from nine different hospitals. Assessments were performed from 7 days to 1 year. Disability, measured by modified Rankin Scale (mRS), was analyzed in terms of good outcome (mRS 0 or 1) and mortality. In addition, functional level was further assessed using Functional Independence Measure (FIM) in aSAH survivors at 1 year post-onset. A subgroup analysis was conducted, with participants further classified into two groups: one with mild-to-moderate disability (mRS 0–3) and another with severe disability (mRS 4 or 5), as reported 7 days after onset. Multiple imputation method was used to handle missing data. In addition, mixed-effects model was used to analyze the trajectory of FIM. Results: A total of 517 patients with aSAH were included. Of these, 246 (47.6%) showed mild-to-moderate disability and 271 (52.4%) showed severe disability at 7 days. At 1 year after onset, the mortality rate was 6.0% and the good outcome was reported in 76.2% of patients. In aSAH survivors at 1 year, FIM showed a significant improvement over time, with a significant difference demonstrated between the subgroups. Age, initial clinical severity, and cognitive function at 7 days were also identified as significant covariates. Conclusions: The majority of patients reporting mild-to-moderate disability at 7 days exhibited good functional outcome, and even among those with severe disability, there was a favorable outcome with continuous improvement in their functional levels. Therefore, proper assessments and effective management should be employed to achieve favorable functional outcomes among aSAH survivors.