To compare the predictive accuracy of the Suicide Intent Scale (SIS), the Suicide Assessment Scale (SUAS), the Karolinska Interpersonal Violence Scale (KIVS), and the Columbia-Suicide Severity Rating Scale (C-SSRS) for suicide attempts and suicides within 3 and 12 months of an episode of self-harm.
..At least 1 suicide attempt was recorded for 216 participants during follow-up, and 19 participants died by suicide. The SUAS and C-SSRS were better than chance in classifying the 114 suicide attempts occurring within the first 3 months; a C-SSRS score ≥ 27 yielded a sensitivity/specificity of 79.8%/51.5% (P < .001). During 1-year follow-up, the SUAS and C-SSRS also performed better than chance, but no cutoff on either instrument gave a sensitivity/specificity of ≥ 80%/≥ 50%. The SIS was the only instrument that could classify suicides correctly. At 3 months, the area under the curve (AUC) was 0.94 (95% CI, 0.89–0.99), and a score ≥ 21 predicted suicide with a sensitivity/specificity of 100%/81.9%, based on only 4 suicides. At 1-year follow-up, the AUC was 0.74 (95% CI, 0.61–0.87), and a score ≥ 17 predicted suicide with a sensitivity/specificity of 72.2%/57.9%.
Conclusions: Instruments that predicted nonfatal repeat suicide attempts did not predict suicide and vice versa. With the possible exception of the prediction of suicide by the SIS in a short time frame, the specificity of these instruments was low, giving them a limited relevance in the prediction of suicidal behaviors.