Suicidal ideation has limited value as a predictive test for suicide, according to research published in BJPsych Open.
The meta-analysis of approximately 70 studies found a moderately strong but highly heterogeneous association between ideation and later suicide (odds ratio [OR] 3.41; 95% CI 2.59-4.49; I2 = 89.4; P≤.001). Pooled sensitivity for later suicide was 41 per cent and pooled specificity was 86 per cent.
Suicidal ideation expressed by psychiatric patients had significantly higher pooled sensitivity (46% v. 22%) and lower pooled specificity (81% v. 96%) than studies conducted in non-psychiatric settings.
The positive predictive value (PPV) of suicidal ideation among non-psychiatric cohorts was significantly lower than among psychiatric samples (0.3% vs 3.9%).
“Enquiring about suicidal ideation will always be a central skill for mental health professionals, not because suicidal ideation is a meaningful forecast of suicide but because patients who express suicidal ideation are making important communications about their inner world and level of psychological distress,” the authors concluded.
“However,” they added, “clinicians should be aware of the statistical limitations of ideation as a screening tool, and not be lured into either a false confidence generated by an absence of ideation, or determinism about the likelihood of suicide if it is present".