Incidence and risk factors of extremely poor functional outcome after burr-hole evacuation of chronic subdural hematoma in octogenarians and nonagenarians- a retrospective cohort analysis

Most studies evaluating burr-hole evacuation of chronic subdural hematoma (CSDH) in older adults focus on mortality, and only few describe patient-centered outcomes. Data on survival with extremely poor functional outcome remain scarce. We aimed to evaluate the incidence of extremely poor functional outcome after burr-hole evacuation of CSDH in octogenarians and nonagenarians, and to describe associated preoperative risk factors. We performed a retrospective analysis of patients ≥ 80 years who underwent burr-hole evacuation for the treatment of CSDH at a single tertiary center from January 2017 to July 2021. Extremely poor functional outcome was defined as Glasgow Outcome Scale – Extended (GOSE) ≤ 3. Multivariable logistic regression models were used to identify independent risk factors for the primary outcome. Among 153 included patients (median age 85 years), 64 patients (42%) had extremely poor outcome. Of these, 52 patients (81%) met the outcome definition due to GOSE = 3 at discharge (survival with total functional dependency), and 12 patients (19%) due to GOSE = 1 (died during hospitalization). Independent risk factors for such poor outcome were pre-hospitalization non-independent living status and pre-existing high burden of comorbidities, with adjusted odds ratios of 6.80 (95% CI 1.96–23.59) and 5.54 (95% CI 1.71–17.91), respectively. Older adults undergoing burr-hole evacuation of CSDH have a significant rate of extremely poor outcome, mostly due to survival with total functional dependency, suggesting an unfavorable harm-benefit ratio of surgical intervention in certain cases. Future research should aim to further establish and validate patient-centered endpoints among older adults with CSDH.