Platform Presentation The Joint Annual Meeting of the Stroke Society of Australasia (SSA) and Smartstrokes 2023

Evaluation of the Melbourne Mobile Stroke Unit Using Data Linkage (#100)

Dominique A Cadilhac 1 2 , Mulugeta Birhanu 1 2 , Henry Zhao 3 , Skye Coote 3 , Damien Easton 3 , Bruce Campbell 3 , Francesca Langenberg 3 , Stephen Davis 3 , Geoffrey Donnan 3 , Leonid Churilov 3 4 , Joosup Kim 1 2
  1. Medicine, Stroke and Ageing Research, Monash University Faculty of Medicine Nursing and Health Sciences, Clayton, VIC, Australia
  2. The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, VIC, Australia
  3. Departments of Medicine and Neurology, Melbourne Brain Centre, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
  4. Australian Stroke Alliance, Melbourne Brain Centre, Parkville, VIC, Australia

Background: The use of mobile stroke ambulances will be expanded in Australia, requiring information on their costs and benefits.

Aims: To assess the hospital costs and outcomes associated with the Melbourne Mobile Stroke Unit (MSU).

Methods: Data from the Australian Stroke Clinical Registry (Victoria) and Melbourne MSU were linked to the Victorian Emergency, Admitted Episodes, cost and deaths datasets, and Ambulance Victoria for the calendar year of 2018. The linkage resulted in 6,355 patient records with ambulance transport. Propensity score matching using age, sex, diagnosis (ischaemic stroke, haemorrhagic stroke or transient ischaemic attack), treating hospital, and postcode identified 202 patients with attendance/transport by the MSU (intervention) and 202 patients transported by standard ambulance services (control). Multiple imputation was used for missing values for costs and the modified Rankin Scale (mRS). Cox proportional hazards regression was used to assess differences in survival.

Results: The mean age of the matched cohort was 78 years, 54% were male, and 71% were ischaemic strokes. Among MSU-attended patients, 75% arrived at hospital in 4.5 hours from onset of symptoms and 27% received thrombolysis. In the control group, 62% arrived at hospital in 4.5 hours and 18% received thrombolysis. The mean cost of hospitalisations within 6 months post-event was $36,457 (95% CI: $28,651, $44,263) in the control group and $38,212 (95% CI: $31,706, $44,718) in the intervention group (p=0.727). At 180 days of follow-up, 151 (75%) of MSU-attended patients and 51 (25%) in the control group were free from disability (mRS scores 0-1, p<0.001). The mortality rate for MSU-attended patients was 51% lower than the control group (hazard ratio: 0.49, 95% CI: 0.30-0.78).

Conclusion: MSU attendance was associated with improved outcomes and lower mortality without a significant increase in overall hospital costs in this preliminary analysis. Future research will include other considerations such as operational costs.