Do socioeconomic disparities in stroke and its consequences decrease in older age?

Abstract

Background: Overall decreased socioeconomic status (SES) has been linked to increased stroke incidence and mortality. Questions remain regarding whether these relationships persist into older age and apply to stroke sequelae. It is also unknown whether the influence of SES on absolute risk - the metric of most importance for population health - differs by age. Methods: A nationally representative cross-sectional survey conducted in 2009 in France involved 26 000 participants, 1653 of whom declared previous stroke. We identified stroke with sequelae and stroke with dependency. SES was characterized as low, medium or high education. We compared the prevalence of stroke outcome across education within age groups (40-59, 60-79 and 80+). Results: Prevalence of stroke was 23.8 per thousand. 65.1% of patients had sequelae and 19.6% were dependent. Variations in the prevalence of stroke and of stroke sequelae were statistically significant only in the youngest generations. A significant education gradient for stroke with dependency was apparent in all three generations, although the prevalence ratio (PR) was highest in the 40-59 (low to high education PR = 8.4, P < 10-3) compared with that in the 80+ (PR = 2.5; P < 10-3); conversely, the absolute difference was of much greater magnitude in the oldest vs. youngest generation (prevalence differences, respectively, 22.8 vs. 1.3 per thousand). Conclusions: SES disparities in the older age group were significant and large in absolute terms when considering more severe outcomes such as stroke dependency. These findings question the ability of universal health care systems to answer equitably the need of the aging population.