Abstract P37: Impact of Onset-To-Treatment Time on Hospital Discharge Destination After Aneurysmal Subarachnoid Haemorrhage - The REDDISH Study

Background and aims: Rapid access to specialised care improves outcomes after aneurysmal subarachnoid haemorrhage (aSAH) but there is limited evidence on the optimal time-to-treatment. We investigated onset-to-treatment time and hospital discharge destination in aSAH. Methods: Consecutive first-ever aSAH patients were retrospectively identified from multiple overlapping sources in two comprehensive cerebrovascular referral centres between 2010-2016. Onset-to-treatment time (hours from onset of symptoms to treatment to secure aneurysm), clinical characteristics, and neurological complications (NINDS classifications) were extracted by clinical data collectors from medical records. Among survivors, we estimated the effect of continuous onset-to-treatment on hospital discharge destination (i.e. home vs. rehabilitation/other hospital as proxy for functional recovery) using logistic regression with adjustment for gender, treatment type (clipping or coiling), hospital presentation (direct admission or transfer), and severity (World Federation of Neurosurgical Societies scale, modified Fisher scale). Non-linear effects were investigated using natural cubic splines. Results: Among 402 survivors at discharge, there was a strong non-linear effect of onset-to-treatment time on odds of being discharged home compared to discharge to rehabilitation independent of severity, gender, treatment type and transfer (see Figure). The greatest benefit to discharge home was evident with treatment at up to 12.5 hours but the benefit remained at up to 20 hours post-onset. Conclusions: aSAH Treatment occurring within 12.5 hours led to greater discharge to home. Our use of continuous modelling provides clarity around optimal treatment times for aSAH to guide clinical practice.