Long-term postoperative prognosis and associated risk factors of chronic subdural hematoma in the elderly

Surgical treatment for chronic subdural hematoma（CSDH）has contributed to good outcome. However, several recent studies have revealed that surgical outcomes for elderly patients were not decisively good. In this study, prognosis of CSDH patients in elderly were analyzed. This study included 232 CSDH patients who were treated in our department and 2 affiliated hospitals, and poor prognosis was defined as aggravation of modified Rankin scale (mRS) at examination comparing with that at discharge, or mRS 3 and higher at examination. We collected data from medical records and questionnaires on the following clinical characteristics of patients: age, sex, findings at admission, medication of antiplatelets and anticoagulants, radiological findings on computed tomography, recurrence, place of discharge, perioperative systemic complications, and mRS at discharge and at examination. The cut-off value of age for poor prognosis of all CSDH patients was 74 years old in this study. In multivariate analysis of all cases, age was prognostic factor for poor outcome:75 years old or higher（p=0.0002）. In this group, mRS at discharge(p=0.0184) and postoperative medical diseases(p