Area factors and suicide: 5-year follow-up of the Northern Ireland population.

BACKGROUND Suicide rates vary markedly between areas but it is unclear whether this is due to differences in population composition or to contextual factors operating at an area level. AIMS To determine if area factors are independently related to suicide risk after adjustment for individual and family characteristics. METHOD A 5-year record linkage study was conducted of 1,116,748 non-institutionalised individuals aged 16-74 years, enumerated at the 2001 Northern Ireland census. RESULTS The cohort experienced 566 suicides during follow-up. Suicide risks were lowest for women and for those who were married or cohabiting. Indicators of individual and household disadvantage and economic and health status at the time of the census were also strongly related to risk of suicide. The higher rates of suicide in the more deprived and socially fragmented areas disappeared after adjustment for individual and household factors. There was no significant relationship between population density and risk of suicide. CONCLUSIONS Differences in rates of suicide between areas are predominantly due to population characteristics rather than to area-level factors, which suggests that policies targeted at area-level factors are unlikely to significantly influence suicides rates.