Socio-economic inequalities in suicide attempts and suicide mortality in Quebec, Canada, 1990-2005

Objectives: Little research has evaluated changes in the association between area deprivation and suicidal behaviour over time. This study investigated patterns in suicide attempts and suicide mortality according to material deprivation in the province of Quebec, Canada between 1990 and 2005. Study design: Ecological analysis. Methods: Data on suicide attempts were extracted from the hospital discharge summary database (n = 47,516) and data on suicides were extracted from the Quebec death file (n = 20,851). Gender- and age-specific (10-24, 25-44, 45-64 and >= 65 years) suicide attempt and mortality rates were calculated for four time periods (1990-1993, 1994-1997, 1998-2001 and 2002-2005) for the entire Quebec population aged 10 years and older residing in 162 communities ranked by decile of material deprivation. Absolute and relative measures of inequality were calculated to summarize differences between the most and least materially deprived areas. Commonly used methods of suicidal behaviour were examined. Results: Differentials in suicide attempt hospitalization between the most and least deprived areas were present for all age groups, and these decreased slightly among males and increased among females over time. Inequalities in suicide attempts were greatest among young adults (age 25-44 years) for both genders, and were smallest among the elderly (>= 65 years). For suicide mortality, differentials increased among females but not males; these differentials were greatest among males and 25-44 year olds, and smallest among the elderly. Differentials in commonly used methods were evident for poisoning hospitalizations in both genders and for hanging deaths among males. Conclusions: In Quebec, differences in suicide attempts and mortality between the most and least materially deprived areas persisted or even increased over time. Inequalities were more pronounced for suicide attempts than for suicide mortality, and were greatest among adults of working age. Strategies to reduce socio-economic differences in suicidal behaviour may be important. (C) 2010 Published by Elsevier Ltd on behalf of The Royal Society for Public Health.