Age-period-cohort analysis of suicide rates in Rio de Janeiro, Brazil, 1979-1998

Abstract

Background: Recent studies in Brazil have demonstrated that suicide rates have been rising over the last years. The objective of this study was to investigate trends in suicide from 1979 to 1998 in Rio de Janeiro State, with emphasis on age, period, and cohort effects.

Method: Age-specific suicide rates from 1979 to 1998 were estimated for males and females based on mortality data obtained from the Brazilian Mortality Information System, and population counts from the 1980, 1991 and 2000 censuses. Poisson regression and graphical methods were used to evaluate age, period and cohort effects.

Results: Suicide rates increased steadily with age, particularly among males. In both males and females, age-adjusted suicide rates decreased until 1992. In 1993, rates started to rise. Cohort effects showed that younger generations had significantly lower rates of suicide than older ones.

Conclusion: The recent rise in suicide rates might be a result of the increasing levels of firearm availability, drug use, and unemployment. Follow-up over longer periods and powerful epidemiological studies are needed to sustain the implication of socio-economic changes in the observed features.