The communication of suicidal intentions: a meta-analysis

Among the myths that are often cited about suicide is that 'people who talk about killing themselves rarely die by suicide', but the evidence seems to contradict this statement. The aim of this study was to conduct a meta-analysis of studies reporting a prevalence of suicide communication (SC), and to examine the diagnostic accuracy of SC towards suicide in case-control reports.

Eligible studies had to examine data relative to completed suicides and report the prevalence of SC. Data relative to sample characteristics, study definition, modality and recipient of the SC were coded.

We included 36 studies, conducted on a total of 14 601 completed suicides. The overall proportion of SC was 44.5% [95% confidence interval (CI) 35.4-53.8], with large heterogeneity (I 2 = 98.8%) and significant publication bias. The prevalence of SC was negatively associated with the detection of verbal communication as the sole means of SC and, positively, with study methodological quality. Based on seven case-control studies, SC was associated with an odds ratio of 4.66 for suicide (95% CI 3.00-7.25) and was characterized by sufficient diagnostic accuracy only if studies on adolescents were removed.

Available data suggest that SC occurs in nearly half of subjects who go on to die by suicide, but this figure is likely to be an underestimate given the operational definitions of SC. At present, SC seems associated with overall insufficient accuracy towards subsequent suicide, although further rigorous studies are warranted to draw definite conclusions on this issue.