BackgroundChronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Patients diagnosed with CSDH’s are often planned for subacute surgery. This means that time from diagnostic CT scan until actual surgery might often be prolonged. There are no previous studies that highlight the effect of delayed intervention in this population.MethodPatients that underwent surgical evacuation for a CSDH at Skåne University Hospital between 1 January 2015 and 31 December 2016 were included in this retrospective cohort study (n = 179). The primary aim was to determine if time from initial diagnosis by head-CT until surgical evacuation had a significant effect on outcome. The following was assessed by mortality, re-operation, number of days spent in hospital, discharge to home/institution, and functional outcome assessed by GOS. Secondary aims were to evaluate the effect of NOAC, vitamin K antagonists, and antiplatelet drugs on time from CT to surgery and re-operation frequency.ResultsMean time from diagnostic CT scan until surgery was 76 h. No significant relationship was found between time from CT to surgical evacuation and number of days spent in hospital, discharge to own home/institution, 1-year mortality, or outcome assessed by GOS at discharge from hospital. The clear majority (95.5%) of the patients were GCS ≥ 13 pre-operatively. No correlation could be seen between use of NOAC, vitamin K antagonists, or antiplatelet drugs regarding the risk for reoperation within 6 months, and no correlation between the use of these agents and time from CT to surgery. The 30-day mortality was too low to draw any statistically significant conclusions (n = 4).ConclusionIn this retrospective cohort study, we could conclude that a delay from initial diagnosis confirming a CSDH to surgical evacuation had no negative effect on outcome when surgery was performed within the time frames and on patients with pre-operatively favorable GCS scores (≥ 13) outlined in our study.