Oral Presentation Australian and New Zealand Stroke Organisation Conference 2026

Estimating rates of young stroke in Victoria and associated risk factors: A population-based study using linked data (139241)

Lachlan L. Dalli 1 2 3 , Muideen T. Olaiya 1 2 3 , Tzu-Yung Kuo 1 2 , Monique F. Kilkenny 1 2 , John H. Mallard 3 4 5 , Dominique A. Cadilhac 1 2 6 , Seana L. Gall 7 , Hazel J. Clothier 3 4 5 , Jim Buttery 3 4 5 8
  1. Stroke and Ageing Research, Department of Medicine, Monash University, Clayton, Victoria, Australia
  2. Victorian Heart Institute, Monash University, Clayton, Victoria, Australia
  3. Epidemiology-informatics Group and Surveillance of Adverse Events Following Vaccination In the Community (SAEFVIC), Murdoch Children's Research Institute, Melbourne, Victoria, Australia
  4. Centre for Health Analytics, Melbourne Children's Campus, Melbourne, Victoria, Australia
  5. Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
  6. The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia
  7. Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
  8. Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia

Background/Aims: Globally, stroke incidence is increasing in young adults, highlighting the importance of investigating risk factors for primary prevention. We aimed to quantify rates of young stroke and determine associated risk factors.

Methods: A population-based study was undertaken using linked administrative data (Vaccine Safety Health Link; 2017-2025). Across Victoria, we identified all unique cases of admitted and fatal acute stroke (ischaemic, intracerebral haemorrhage, unspecified) in young adults (18-55 years). Age-standardised event rates were calculated using population denominators. Factors associated with stroke were explored using multivariable logistic regression, with non-stroke controls randomly sampled from admissions data.

Results: Over nine years, 7011 strokes (71% ischaemic; 7% fatal) occurred among 6505 young adults (median age 48 years; 56% male), at an age-standardised rate of 25.0 events (95% CI 24.4–25.6) per 100,000 person-years. Age-standardised rates were greater in 2025 than 2017 (rate ratio 1.28 [95% CI 1.15–1.42]). Using a random 10% sample of non-stroke controls (N=191,657; median age 38 years; 47% male), factors associated with stroke included hypertension (odds ratio [OR] 4.87 [95% CI: 4.62–5.14]), dyslipidaemia (OR 3.08 [95% CI: 2.68–3.54]), atrial fibrillation (OR 1.35 [95% CI: 1.22–1.49]), diabetes (OR 1.29 [95% CI: 1.22–1.36]), and smoking (OR 1.35 [95% CI: 1.22–1.49]). Whereas, being vaccinated in the prior month was associated with reduced stroke (OR 0.79 [95% CI: 0.67–0.93]).

Conclusion: Stroke rates are increasing in young Victorians and are strongly associated with traditional risk factors, while vaccination may be protective. These preliminary findings warrant further epidemiological investigation.