Oral Presentation Australian and New Zealand Stroke Organisation Conference 2025

Are associations between socioeconomic deprivation and stroke independent of ethnicity, rurality and other common risk factors? A New Zealand whole population linkage study (123238)

Mina Whyte 1 , Anna Ranta 1 2 , Jeroen Douwes 3 , Marine Corbin 3 , Hayley Denison 3 , Rita Krishnamurthi 4 , Balakrishnan Nair 4 , Varsha Parag 5 , Bruce Arroll 5 , Alan P Barber 5 , Suzanne Barker-Collo 5 , Derrick Bennett 6 , Paul Brown 7 , Dominique A Cadilhac 8 , Daniel Exeter 5 , Yogini Ratnasabapathy 9 , El-Shadan Tautolo 4 , Braden Te Ao 5 , Amanda Thrift 8 , Bronwyn Tunnage 4 , Brigitte van Gils 4 , Valery L Feigin 4
  1. Medicine, University of Otago, Wellington, New Zealand
  2. Neurology, Te Whatu Ora, Wellington, New Zealand
  3. Massey University, Wellington, New Zealand
  4. Auckland University of Technology, Auckland, New Zealand
  5. University of Auckland, Auckland, New Zealand
  6. University of Oxford, Oxford, United Kingdom
  7. University of California - Merced, Merced, United States of America
  8. Monash University, Melbourne, Australia
  9. Te Whatu Ora, Auckland, New Zealand

Background/Aim: Socioeconomic factors are important determinants of health and wellbeing. The aim of this study was to assess the associations between socioeconomic deprivation and stroke incidence in New Zealand, and whether these were independent of ethnicity, rurality and common risk factors for stroke.

Methods: Using linked data, we identified incident stroke cases for the 2018 resident population. Socioeconomic deprivation was measured using the New Zealand Index of Deprivation (NZDep) and the Index of Multiple Deprivation (IMD), categorized from the least (decile 1) to the most deprived (decile 10). Logistic regression controlling for age, sex, ethnicity, rurality, hypertension, diabetes, atrial fibrillation, hyperlipidaemia and smoking yielded adjusted odds ratios (AOR).

Results: Among 4,815,033 residents, 7,155 persons were admitted with their first-ever stroke. Greater deprivation was associated with an increased risk of stroke in analyses controlling for sex and age. For example, people living in the most deprived area had the highest risk of stroke (AOR=1.33, CI95: 1.17-1.51 (NZDep), AOR=1.43, CI95: 1.2-1.61 (IMD); decile 10 v decile 1). Further adjustment for ethnicity, rurality, and medical risk factors attenuated these associations (2-15% for ethnicity and 1.7-7% for medical risk factors), but associations remained statistically significant for deprivation. Attenuation was most evident in those most deprived.

Conclusion: Socioeconomic deprivation is an independent risk factor for stroke in New Zealand, which is only partially explained by ethnicity and medical risk factors. Addressing the causes of socioeconomic deprivation as well as focusing efforts to lower modifiable risk factors, especially in high deprivation areas, may lower stroke risk.