Excess mortality by suicide in high-risk subgroups of suicide attempters: a prospective study of standardised mortality rates in suicide attempters examined at a medical emergency inpatient unit

Abstract

Objectives: The primary aim of the present study was to investigate the putative excess mortality by suicide in suicide attempters. As a secondary aim, we investigate excess mortality in specific, clinically relevant subgroups: individuals with repeated suicide attempts (RA); individuals who used violent method at the attempt (VA); and those who scored high on the Suicide Intent Scale (HS) at the time of the baseline attempt. Finally, we investigate excess mortality in men and women separately and within 5 years and over 5 years after hospital admission for attempted suicide.

Design: Prospective register-based follow-up for 21-32 years. Standardised mortality ratio (SMR) was calculated for suicide using national census data. Clinically relevant subgroups were investigated separately.

Setting: Medical emergency inpatient unit in the south of Sweden.

Participants: 1039 individuals who were psychiatrically assessed at admission to medical inpatient care for attempted suicide between 1987 and 1998.

Outcome measure: Suicide.

Results: The overall SMR for suicide was 23.50 (95% CI 18.68 to 29.56); significantly higher (p<0.001) among women (30.49 (95% CI 22.27 to 41.72)) than men (18.61 (95% CI 13.30 to 26.05)). Mortality was highest within the first 5 years after the index suicide attempt (48.79 (95% CI 35.64 to 66.77)) compared with those who died after 5 years (p<0.001) (14.74 (10.53 to 20.63)). The highest independent SMR was found for VA (70.22 (95% CI 38.89 to 126.80)). In a regression model including RA, VA and HS all contributed significantly to excess suicide mortality.

Conclusions: An elevated risk of premature death by suicide was found in suicide attempters compared with the general population. Assessment of previous suicide attempts is important, even though the attempt/s may have occurred decades ago. When assessing suicide risk, clinicians should consider repeated attempts and whether the attempts involved high suicidal intent and violent method. Healthcare interventions may benefit from targeting identified subgroups of attempters.

Keywords: adult psychiatry; epidemiology; psychiatry; suicide & self-harm.