Predictive Validity of the K-CAT-SS in High-Risk Adolescents and Young Adults

Objective: Suicide is a leading cause of death in adolescents and young adults and has increased substantially in the past 15 years. Accurate suicide risk stratification based on rapid screening can help reverse these trends. This study aimed to assess the ability of the Kiddie Computerized Adaptive Test Suicide Scale (K-CAT-SS), a brief computerized adaptive test of suicidality, to predict suicide attempts (SAs) in high-risk youth.

Method: A total of 652 participants (age range, 12-24 years), 78% of whom presented with suicidal ideation or behavior, were recruited within 1 month of mental health care contact. The K-CAT-SS, scaled from 0 to 100, was administered at baseline, and participants were assessed at about 1, 3, and 6 months after intake. Weekly incidence of SAs was assessed using the Adolescent Longitudinal Interval Follow-up Evaluation and Columbia-Suicide Severity Rating Scale. A secondary outcome was suicidal behavior, including aborted, interrupted, and actual SAs.

Results: The K-CAT-SS showed a 4.91-fold increase in SAs for every 25-point increase in the baseline score (95% CI 2.83-8.52) and a 3.51-fold increase in suicidal behaviors (95% CI 2.32-5.30). These relations persisted following adjustment for prior attempts; demographic variables including age, sex, gender identity, sexual orientation, and race/ethnicity; and other measures of psychopathology. No moderating effects were identified. At 3 months, area under the receiver operating characteristic curve was 0.83 (95% CI 0.72-0.93) for 1 or more SAs.

Conclusion: The K-CAT-SS is an excellent tool for suicide risk stratification, particularly in higher-risk populations where other measures have shown lower predictive validity.