Introduction and aim: There are limited comparative data on social inequalities in stroke morbidity across Europe. We aimed to assess the magnitude of educational class inequalities in stroke mortality, incidence and 1-year case-fatality in European populations.
Methods: The MORGAM study comprised 45 cohorts from Finland, Denmark, Sweden, Northern Ireland, Scotland, France, Germany, Italy, Lithuania, Poland and Russia, mostly recruited in mid 1980s-early 90s. Baseline data collection and follow-up (median 12 years) for fatal and non-fatal strokes adhered to MONICA-like procedures. Stroke mortality was defined according to the underlying cause of death (ICD-IX codes 430-438 or ICD-X I60-I69). We derived 3 educational classes from population-, sex- and birth year-specific tertiles of years of schooling. We estimated the age-adjusted difference in event rates, and the age- and risk factor-adjusted hazard ratios (HRs), between the bottom and the top of the educational class distribution from sex- and population-specific Poisson and Cox regression models, respectively. The association between 1-year case-fatality and education was estimated through logistic models adjusted for risk factors.
Results: Among the 91,563 CVD-free participants aged 35-74 at baseline, 1037 stroke deaths and 3902 incident strokes occurred during follow-up. Low education accounted for 26 additional stroke deaths per 100,000 person-years in men (95%CI: 9 to 42), and 19 (7 to 32) in women. In both genders, inequalities in fatal stroke rates were larger in the East EU and in the Nordic Countries populations. The age-adjusted pooled HRs of first stroke, fatal or non-fatal, for the least educated men and women were 1.52 (95%CI: 1.29-1.78) and 1.51 (1.25-1.81), respectively, consistently across populations. Adjustment for smoking, blood pressure, HDL-cholesterol and diabetes attenuated the pooled HRs to 1.34 (95%CI: 1.14-1.57) in men and 1.29 (1.07-1.55) in women. A significant association between low education and increased 1-year case-fatality was observed in Northern Sweden only.
Conclusions: Social inequalities in stroke incidence are widespread in most European populations, and less than half of the gap is explained by major risk factors.