Suicide and pathways between different socioeconomic indicators: a register-based study of Finnish women

Netta Mäki, University of Helsinki
Pekka Martikainen, University of Helsinki

Suicide is the fourth most common cause of death in working age. Among men socioeconomic status is strongly and inversely associated with suicide mortality, but very little is known about socioeconomic differences in female suicide mortality. We studied the pathways of different socioeconomic indicators – education, occupation-based social class and income – on suicide among Finnish women aged 25–64, and assessed to what extent their effects are direct, or explained or mediated by other socioeconomic indicators. Furthermore, because main economic activity is closely related to many indicators of socioeconomic status and because family type is associated with female suicide, we also studied their effects. Individual level data from the 1990 census linked to the death register for the years 1991–2001 were used. Altogether over 14 million person-years were observed and 2137 suicides were committed. We calculated age-adjusted death rates and relative indeces of inequality (RII) in Poisson regression models. Our results showed that all socioeconomic indicators were associated with suicide mortality: RII was 1.72 (95% CI 1.47–2.03) for education, 1.97 (1.68–2.30) for social class and 2.13 (1.82–2.49) for income. However, almost all of the effect of education was mediated by social class. Fifteen per cent of the effect of social class was explained by education and 40 per cent was mediated by income. The effect of income on suicide was mainly explained by economic activity and family type. In conclusion, net of other indicators occupation-based social class is a strong determinant of socioeconomic differences in female suicide mortality, while the effects of other indicators are either explained by social class or social class mediates their effects. Actions aimed at preventing female suicide should target low social class groups. Research on socioeconomic differences in suicide mortality should better aim at disentangling causal pathways between the different indicators.