Time to surgery and postoperative functional outcomes among patients with chronic subdural haematomas

BACKGROUND: Chronic subdural haematoma (cSDH) is a common neurological condition. Surgery remains the preferred treatment for symptomatic patients. Delays in surgery can occur due to logistical, clinical or medication-related factors. We investigated the relationship between time to surgery and postoperative functional outcomes in symptomatic cSDH. METHOD: Retrospective multicentre cohort study conducted from 2012 to 2023 across five UK neurosurgical units within the National Health Service system, with 1-year follow-up. Of the 1508 patients referred for surgical intervention for cSDH, 1015 remained for analysis. 213 were excluded due to missing data and 280 for ≥30-day wait for surgery to mitigate extreme outliers. Postoperative functional outcome was assessed using the modified Rankin Scale, categorised as 'favourable' (0-3) and 'unfavourable' (4-6). Predictors of outcome were identified using multivariable logistic regression, and the association between time to surgery and outcome was evaluated by marginal effects analysis. Factors influencing time to surgery were analysed by multivariate linear regression. RESULTS: Of 1015 patients, 838 (82.6%) had 'favourable' outcomes and 177 (17.4%) had 'unfavourable' outcomes. Surgical delay was significantly longer in patients with 'unfavourable' outcomes (mean 4.4 vs 2.9 days, p