Influence of socioeconomic status on the incidence of aneurysmal subarachnoid haemorrhage and clinical recovery.

Background: The relevance of socioeconomic status (SES) on the incidence of aneurysmal subarachnoid haemorrhage (aSAH) and discharge functional outcomes following treatment is not clear.

Methods: A retrospective cross-sectional study was performed on data retrieved from the Nationwide Hospital Morbidity Database for all aSAH cases in Australia between 2012 and 2018. Information on patient characteristics, procedures performed, discharge disposition and SES were extracted. SES data was derived from classifications by the Australian Bureau of Statistics. Putative risk factors were evaluated with univariate and multivariate logistic regression analysis to identify independent predictor of unfavourable discharge outcomes (defined as death or dependency).

Results: A total of 3,591 low SES patients (49.8%) were identified in our study cohort. Average crude incidence of aSAH was persistently higher among the SES disadvantaged (6.6 cases per 100,000 person-years, 95% CI 6.3 - 6.8), compared to the SES advantaged group (4.1 cases per 100,000 person-years, 95% CI 4.0-4.2) (p < 0.0001). Patients in the Low SES group were more likely to be active smokers, have type 2 diabetes mellitus, or live in non-metropolitan residence, and have overall worse discharge functional outcomes (27.7% versus 24.5%, p = 0.0015). Adjusting for well-established risk factors such as older age, and intracranial bleed (ICH and/or IVH), disadvantaged SES remained a significant predictor of poor discharge outcome following aSAH (p = 0.0003).

Conclusion: aSAH occurs more frequently among low SES communities, and once ruptured, there is a greater risk of poor recovery..