Non-surgical patient characteristics best predict outcome after 6 months in patients surgically treated for chronic subdural haematoma.

BACKGROUND: Chronic subdural haematoma (CSDH) is one of the most common conditions encountered in neurosurgical practice. After surgery, the patients often improve dramatically; but their long-term outcome is more uncertain. The purpose of this study was to investigate predictors of outcome 6 months after surgery. METHODS: Retrospective data were collected on patients in Orebro County, Sweden, who had undergone surgery for CSDH at the Orebro University Hospital between 2013 and 2019. The outcomes were defined as favourable or unfavourable in terms of the modified Rankin Scale (mRS). A favourable outcome was defined as either mRS 0-2 or an unchanged mRS score in patients scoring 3-5 before surgery. From the variables in the data collected, a multiple logistic regression model was constructed. RESULTS: The study comprised 180 patients, of whom 134 (74.4%) were male. Median age was 79.2 years (IQR 71.7-85.5), and 129 (71.7%) patients had a favourable outcome at 6 months. In the group with an unfavourable outcome, 18 (10%) had died and 33 (18.3%) had either lost their independence in daily living or become somewhat less independent. The final multiple logistic regression model consisted of pre-surgery variables only: age (OR 0.92, 95% CI 0.87-0.97), CRP (OR 0.96, 95% CI 0.94-0.99), GCS > 13 (OR 3.66, 95% CI 1.09-12.3), Hb (OR 1.03, 95% CI 1.00-1.05), and ASA score < 3 (OR 2.58, 95% CI 0.98-6.79). The whole model had an AUC of 0.88. CONCLUSION: CSDH requiring surgery is associated with high morbidity and mortality at 6 months after surgery. Age, CRP, GCS, Hb and ASA score on admission for surgery are the variables that best predicts outcome. This knowledge can help to identify the patients at greatest risk for an unfavourable outcome, who may need additional support from the health care system. UNSTRUCTURED ABSTRACT: Chronic subdural haematoma (CSDH) is one of the most common conditions encountered in neurosurgical practice. After surgery, the patients often improve dramatically; but their long-term outcome is more uncertain. The purpose of this study was to investigate predictors of outcome, in terms of the modified Rankin Scale (mRS), 6 months after surgery. The study comprised 180 patients, of whom 134 (74.4%) were male. Median age was 79.2 years (IQR 71.7-85.5), and 129 (71.7%) patients had a favourable outcome at 6 months. In the group with an unfavourable outcome, 18 (10%) had died and 33 (18.3%) had either lost their independence in daily living or become somewhat less independent. The final multiple logistic regression model consisted of pre-surgery variables only: age (OR 0.92, 95% CI 0.87-0.97), CRP (OR 0.96, 95% CI 0.94-0.99), GCS > 13 (OR 3.66, 95% CI 1.09-12.3), Hb (OR 1.03, 95% CI 1.00-1.05), and ASA score < 3 (OR 2.58, 95% CI 0.98-6.79). The whole model had an AUC of 0.88. In conclusion, CSDH requiring surgery is associated with high morbidity and mortality at 6 months after surgery. Age, CRP, GCS, Hb and ASA score on admission for surgery are the variables that best predicts outcome. This knowledge can help to identify the patients at greatest risk for an unfavourable outcome, who may need additional support from the health care system.

A Validation Study of Kwon's Prognostic Scoring System for Chronic Subdural Hematoma.

OBJECTIVE: Surgery for chronic subdural hematoma is one of the most frequent operations in neurosurgical practice. Chronic subdural hematoma mostly afflicts the elderly population. In 2018, Kwon and co-workers, published the Kwon scoring system (KSS), whereby 6 clinical and radiological factors are used to facilitate, and promote quality in, surgical decision-making and counseling of relatives. The aim of this study is to validate the KSS. METHODS: Patients operated on for unilateral chronic subdural hematoma at Örebro University Hospital, Sweden, between 2013 and 2019 constituted the study population. General data and the 6 outcome predictors according to the KSS were extracted from the electronic patient records. The preoperative modified Rankin Scale score and the postoperative 6-month modified Rankin Scale score were assessed. RESULTS: We identified 133 patients (69.2% male) with a median age of 80.2 years (interquartile range 72.6-85.9). The median Glasgow Coma Scale score at admission was 15; 57.1% had motor deficits and 36.81% were disoriented. For 39.1% of the patients, the prognosis was a favorable outcome (modified Rankin Scale 0-1) at 6 months. The median KSS score was 9; 63.9% of the patients scored ≥9, and 36 (42.4%) of these patients actually achieved a favorable outcome. This corresponds to a prediction model sensitivity of 0.667 and specificity of 0.424. A receiver operator characteristic curve analysis of the model yielded an area under the receiver operator characteristic curve of 0.62441. CONCLUSIONS: In our material, the KSS did not predict outcome precisely enough to base treatment decisions or counseling of relatives on the scores obtained.