Socioeconomic deprivation, ethnicity, and stroke mortality in Greater London and south east England

Objective and setting - To examine geographical variation in stroke mortality in Greater London compared with the surrounding South East Region of England. Design - Cross sectional, ecological analysis based on electoral wards. Subjects - Resident population aged 45 years or more. Main outcome measure - Age specific stroke mortality rates in five age bands, 1986-92. Main results - In the 45-54 years age band, stroke mortality rate ratios (95% confidence intervals) relative to the surrounding south east were 2.09 (1.81,2.4) for Inner London and 1.31 (1.15,1.5) for Outer London for men and 1.64 (1.4,1.93) and 1.13 (0.98,1.31) respectively for women. This gradient diminished and reversed with increasing age. In the 85+ age band, rate ratios were 0.82 (0.76,0.89) for Inner London and 0.89 (0.84,0.94) for Outer London for men and 0.8 (0.75,0.85) and 0.88 (0.84,0.92) respectively for women. Carstairs deprivation index and the percentages of Afro-Caribbean men and women and Irish born men were significantly and positively correlated with stroke mortality at the ward level. The Carstairs effect diminished with increasing age. Adjustment for these variables diminished or abolished the higher stroke mortality risks in London for younger people but had little effect on the lower risks for older Londoners. Conclusions - Higher rates of stroke mortality among middle aged adults in Greater London, compared with the surrounding South East Region, are associated with socioeconomic deprivation and ethnicity. These factors do not explain the relatively lower stroke mortality among older Londoners.