Are recent increases in deliberate self-harm associated with changes in socio-economic conditions? An ecological analysis of patterns of deliberate self-harm in Bristol 1972-3 and 1995-6

Background. The incidence of deliberate self-harm (DSH) in Britain has increased markedly over the last 30 years. Reasons for this rise are not clear. We have investigated whether changes in the social and economic environment underlie any of the recent increase in DSH incidence. Methods. An ecological analysis was used to assess associations between changes in census-based measures of the social and economic environment - the Townsend Deprivation Index and a three-factor social fragmentation index - and changes in age- and sex-specific hospital attendance rates for DSH for the 28 wards of the city of Bristol between 1972-3 and 1995-6. Results. There were significant cross-sectional associations between the Townsend Index and rates of DSH in both males and females in both time periods. Increases in Townsend Index were also associated with increases in DSH. This association was statistically significant at the 5% level in 25-34 year-old females. Associations with the social fragmentation index were weak, although our index was based on rather limited data. Conclusions. This analysis suggests that changes in levels of socio-economic deprivation may influence area-specific patterns of DSH and such changes may have contributed to recent rises in DSH.