Predictors of Functional Outcome After Subdural Hematoma: A Prospective Study

Abstract

Although the incidence of subdural hematoma (SDH) has increased in the US in the last decade, limited prospective data exist examining risk factors for poor outcome. A prospective, observational study of consecutive SDH patients was conducted from 7/2008 to 11/2011. Baseline clinical data, hospital and surgical course, complications, and imaging data were compared between those with good versus poor 3-month outcomes (modified Rankin Scores [mRS] 0-3 vs. 4-6). A multivariable logistic regression model was constructed to identify independent predictors of poor outcome. 116 SDH patients (18 acute, 56 mixed acute/subacute/chronic, 42 subacute/chronic) were included. At 3 months, 61 (53 %) patients had good outcomes (mRS 0-3) while 55 (47 %) were severely disabled or dead (mRS 4-6). Of those who underwent surgical evacuation, 54/94 (57 %) had good outcomes compared to 7/22 (32 %) who did not (p = 0.030). Patients with mixed acuity or subacute/chronic SDH had significantly better 3-month mRS with surgery (median mRS 1 versus 5 without surgery, p = 0.002) compared to those with only acute SDH (p = 0.494). In multivariable analysis, premorbid mRS, age, admission Glasgow Coma Score, history of smoking, and fever were independent predictors of poor 3-month outcome (all p < 0.05; area under the curve 0.90), while SDH evacuation tended to improve outcomes (adjusted OR 3.90, 95 % CI 0.96-18.9, p = 0.057). Nearly 50 % of SDH patients were dead or moderate-severely disabled at 3 months. Older age, poor baseline, poor admission neurological status, history of smoking, and fever during hospitalization predicted poor outcomes, while surgical evacuation was associated with improved outcomes among those with mixed acuity or chronic/subacute SDH.