A risk calculator to predict suicide attempts among individuals with early-onset bipolar disorder
Abstract
Objectives
To build a one-year risk calculator (RC) to predict individualized risk for suicide attempt in early-onset bipolar disorder.
Methods
Youth numbering 394 with bipolar disorder who completed ≥2 follow-up assessments (median follow-up length = 13.1 years) in the longitudinal Course and Outcome of Bipolar Youth (COBY) study were included. Suicide attempt over follow-up was assessed via the A-LIFE Self-Injurious/Suicidal Behavior scale. Predictors from the literature on suicidal behavior in bipolar disorder that are readily assessed in clinical practice were selected and trichotomized as appropriate (presence past 6 months/lifetime history only/no lifetime history). The RC was trained via boosted multinomial classification trees; predictions were calibrated via Platt scaling. Half of the sample was used to train, and the other half to independently test the RC.
Results
There were 249 suicide attempts among 106 individuals. Ten predictors accounted for >90% of the cross-validated relative influence in the model (AUC = 0.82; in order of relative influence): (1) age of mood disorder onset; (2) non-suicidal self-injurious behavior (trichotomized); (3) current age; (4) psychosis (trichotomized); (5) socioeconomic status; (6) most severe depressive symptoms in past 6 months (trichotomized none/subthreshold/threshold); (7) history of suicide attempt (trichotomized); (8) family history of suicidal behavior; (9) substance use disorder (trichotomized); (10) lifetime history of physical/sexual abuse. For all trichotomized variables, presence in the past 6 months reliably predicted higher risk than lifetime history.
Conclusions
This RC holds promise as a clinical and research tool for prospective identification of individualized high-risk periods for suicide attempt in early-onset bipolar disorder.
CONFLICT OF INTEREST
Dr. T. Goldstein reports grants from NIMH, The American Foundation for Suicide Prevention (AFSP), University of Pittsburgh Clinical and Translational Science Institute (CTSI), and The Brain and Behavior Foundation and royalties from Guilford Press, outside the submitted work. Dr. Hafeman reports grants from NIMH and the Brain and Behavior Research Foundation. Dr. Weinstock reports research support from NIMH, NCCIH, the NIH Office of Behavioral Social Sciences Research (OBSSR), the Warren Alpert Foundation and the National Institute of Justice (NIJ). Dr. Yen reports research support from NIMH, the National Center for Complimentary and Integrative Health (NCCIH), and AFSP. Dr. B. Goldstein reports grant funding from Brain Canada, Canadian Institutes of Health Research, Heart & Stroke Foundation, NIMH, and the departments of psychiatry at the University of Toronto, and acknowledges salary support from the RBC Investments Chair, held at the Centre for Addiction and Mental Health and the University of Toronto department of psychiatry. Dr. Keller reports research support from NIMH and the John J. McDonnell and Margaret T. O'Brien Foundation. Dr. Strober reports research support from NIMH, and support from the Resnick Endowed Chair in Eating Disorders. Dr. Ryan reports grants from NIH and Axsome Therapeutics. Dr. Birmaher reports grants from NIMH, royalties from Random House, UpToDate and Lippincott, Williams & Wilkins. Mr. Merranko, Ms. Gill, Ms. Liao, Mr. Sewall and Ms. Hower report no financial relationships with commercial interests.
Open Research
DATA AVAILABILITY STATEMENT
The investigative team contributes data and associated documentation in compliance with NIMH Data Sharing Policy through the National Database for Clinical Trials Related to Mental Illness (NDCT) as per NOT-MH-14-015. Per the NIMH Data Repositories Data Access Agreement and Use Certification, in order to gain access to data from this project, outside Investigators must submit a detailed proposal of the study aims, hypotheses to be tested, variables/constructs and analytic approach to be used.
