Abstract 2630: Lower Socioeconomic Status is Associated with Higher Rates of First Hospitalization for Stroke and Subsequent Case Fatality: A Population Study of 5.1 Million People in Scotland 1985–2005

Abstract

Introduction Small, age or geographically restricted studies suggest that stroke incidence and case fatality increase with lower socioeconomic status (SES). We examined the relationship between SES and stroke incidence and case fatality in a whole country. Methods Linked morbidity and mortality data were used to identify all first hospitalizations in Scotland where stroke was coded in the principal diagnostic position at discharge from 1986 –2005. SES was measured using the quintiles of Carstairs index of deprivation (quintile 1= most affluent, 5=most deprived). Age and sex specific incidence rates by SES were calculated. Cox regression was used to model case-fatality by SES at 30 days, 1 and 5 years adjusted for comorbidities. Results From 1986 –2005 73,676 men and 88,808 women were admitted with a first stroke. In men (women) 11575 (14713) occurred in individuals in deprivation quintile 1 and 15800 (19022) in quintile 5. Rates of stroke were higher in the most deprived vs the most affluent individuals. In 1986, in men aged <55, 55– 64, 65–74, 75– 84 and >85 years, the rate ratios (deprived vs affluent) were 2.05(1.46 –2.87), 1.82(1.38 –2.38), 1.56(1.27–1.92), 1.06(0.87–1.31) and 1.16(0.78 –1.74) respectively. In women the respective ratios were 2.57(1.71–3.87), 2.06(1.50 –2.83), 1.62(1.32–1.99), 1.27(1.09 –1.49) and 1.36(1.07–1.74). These gradients persisted from 1986 to2005 in both men and women and in all ages. Adjusted case fatality did not vary by SES at 30 days,, HR (deprived vs affluent) = 1.01(95%CI 0.96 –1.06) in men, 1.03(0.99 –1.08) in women. However, at 30 days-1 year the HR was 1.17(1.09 –1.24) in men and 1.11 (1.05–1.17) in women. At 1–5 years the HRs were 1.20(1.13–1.26) in men and 1.14(1.09 –1.20) in women. The effect of SES on case fatality and hospitalization rates did not vary by year or stroke subtype (p for interactions >0.05). Conclusion Not only are stroke hospitalization rates highest in the most deprived individuals, but adjusted longer term case fatality after discharge is also higher. There is no evidence that this disparity is decreasing over time.