Suicide Intent Scale in the prediction of suicide

Abstract Objective To assess the predictive value of the Suicide Intent Scale in patients with high suicide risk. The secondary aim was to assess if the use of the factors of the Suicide Intent Scale may offer a better predictive value in suicide risk detection. Finally a shorter version of the scale was created after an item analysis. Method Eighty-one suicide attempters were assessed with the Beck's Suicide Intent Scale (SIS). All patients were followed up for cause of death. Receiver-operating characteristic (ROC) curves and tables were created to establish the optimal cut-off values for SIS and SIS factors to predict suicide. Results Seven patients committed suicide during a mean follow up of 9.5 years. The major finding was that mean SIS scores distinguished between suicides and survivors. The positive predictive value was 16.7% and the Area Under Curve (AUC) was 0.74. Only the planning subscale reached statistical significance. Four items were used to test a shorter version of the SIS in the suicide prediction. The positive predictive value was 19% and the AUC was 0.82. Conclusions The Suicide Intent Scale is a valuable tool in clinical suicide risk assessment, a shorter version of the scale may offer a better predictive value.