The effects of household income distribution on stroke prevalence and its risk factors of high blood pressure and smoking: a cross-sectional study in Saskatchewan, Canada

Abstract

Background: Stroke is a major chronic disease and a common cause of adult disability and mortality. Although there are many known risk factors for stroke, lower income is not one that is often discussed. Aims: To determine the unadjusted and adjusted association of income distribution on the prevalence of stroke in Saskatchewan, Canada. Methods: Information was collected from the Canadian Community Health Survey conducted by Statistics Canada for 2000–2008. In total, 178 variables were analysed for their association with stroke. Results: Prior to statistical adjustment, stroke was seven times more common for lower income residents than higher income residents. After statistical adjustment, only four covariates were independently associated with stroke prevalence, including having high blood pressure (odds ratio (OR) = 2.62; 95% confidence interval (CI) = 2.12–3.24), having a household income below CAD$30,000 per year (OR = 2.49; 95% CI = 1.88–3.29), being a daily smoker (OR = 1.36; 95% CI = 1.16–1.58) and being physically inactive (OR = 1.27; 95% CI = 1.13–1.43). After statistical adjustment, there were five covariates independently associated with high blood pressure prevalence, including having a household income below CAD$30,000 per year (OR = 1.52; 95% CI = 1.41–1.63). After statistical adjustment, there were five covariates independently associated with daily smoking prevalence, including having a household income below CAD$30,000 per year (OR = 1.29; 95% CI = 1.25–1.33). Conclusions: Knowledge of disparities in the prevalence, severity, disability and mortality of stroke is critically important to medical and public health professionals. Our study found that income distribution was strongly associated with stroke, its main disease intermediary – high blood pressure – and its main risk factor – smoking. As such, income is an important variable worthy of public debate as a modifiable risk factor for stroke.