Relation between parasuicide, suicide, psychiatric admissions, and socioeconomic deprivation

OBJECTIVE: To examine the relations between parasuicide, suicide, psychiatric inpatient admissions, and socioeconomic deprivation. DESIGN: Ecological analysis with data from routine information systems and the 1991 census. SETTING: 24 localities in the area covered by the Bristol and District Health Authority (population 817,000), consisting of aggregations of neighbouring wards, with an average population of 34,000. SUBJECTS: 6089 subjects aged over 10 years admitted to hospital after parasuicide between April 1990 and March 1994; 997 suicides occurring 1982-91; 4763 subjects aged 10-64 years admitted with acute psychiatric illness between April 1990 and March 1994. RESULTS: Localities varied significantly in standardised admission ratios for parasuicide and standardised mortality ratios for suicide (P < 0.001). Spearman's rank correlation coefficient between the standardised mortality ratio for suicide and standardised admission ratio for parasuicide was 0.73 (95% confidence interval 0.46 to 0.88). Correlation between parasuicide and Townsend score was 0.86 (0.70 to 0.94) and between suicide and Townsend score 0.73 (0.46 to 0.88). The partial correlation coefficient between suicide and parasuicide after the Townsend score was adjusted for was 0.29 (-0.13 to 0.62). The correlation between standardised admission ratio for parasuicide and standardised admission ratio for psychiatric illness was 0.76 (0.51 to 0.89) and between standardised mortality ratio for suicide and standardised admission ratio for psychiatric illness was 0.72 (0.45 to 0.87). CONCLUSION: A strong ecological association exists between suicide and parasuicide, with socioeconomic deprivation accounting for much of this relation. This strong association provides supporting evidence for the importance of social policy measures in attaining Health of the Nation targets on mental health.