Socioeconomic Status and the Risk of Stroke Recurrence: Persisting Gaps Observed in a Nationwide Swedish Study 2001 to 2012.

Abstract

This nationwide observational study aimed to investigate how socioeconomic status is associated with risk of stroke recurrence and how possible associations change over time. This study included 168 295 patients, previously independent in activities of daily living, with a first-ever stroke in the Swedish Stroke Register (Riksstroke) 2001 to 2012. Riksstroke was linked with Statistics Sweden as to add individual information on education and income. Subdistribution hazard regression was used to analyze time from 28 days after first stroke to stroke recurrence, accounting for the competing risk of other causes of death. Median time of follow-up was 3.0 years. During follow-up, 23 560 patients had a first recurrent stroke, and 53 867 died from other causes. The estimated cumulative incidence of stroke recurrence was 5.3% at 1 year, and 14.3% at 5 years. Corresponding incidence for other deaths were 10.3% and 30.2%. Higher education and income were associated with a reduced risk of stroke recurrence. After adjusting for confounding variables, university versus primary school education returned a hazard ratio of 0.902; 95% confidence interval, 0.864 to 0.942, and the highest versus the lowest income tertile a hazard ratio of 0.955; 95% confidence interval, 0.922 to 0.989. The risk of stroke recurrence decreased during the study period, but the inverse effect of socioeconomic status on risk of recurrence did not change significantly. Despite a declining risk of stroke recurrence over time, the differences in recurrence risk between different socioeconomic groups remained at a similar level in Sweden during 2001 to 2012.