Improper study design precludes valid effect estimates in important suicide prevention research.

Area of Science:

• Psychiatry
• Clinical Psychology
• Epidemiology

Background:

• Observational study designs for evaluating suicide risk diagnostic tests are compromised by confounding by indication and protopathic bias.
• Suicide prevention interventions in high-risk groups distort accuracy estimates (sensitivity, specificity) of diagnostic tests.
• The term "prediction of suicide" is conceptually flawed and inappropriate for current research contexts.

Discussion:

• Accuracy metrics like sensitivity and specificity are misinterpreted when applied to diagnostic tests for suicide risk in open prospective trials.
• The influence of confounding factors, such as suicide prevention, invalidates the demonstration of diagnostic test utility in open study designs.
• Existing research conclusions on the efficacy of suicide risk diagnostic tests require reevaluation due to methodological limitations.

Key Insights:

• Simple arithmetic mechanisms demonstrate that sensitivity and specificity cannot be reliably estimated in open trials for suicide risk assessment.
• Diagnostic tests may possess inherent value in assessing suicidological aspects, but this cannot be proven through flawed study designs.
• The fundamental illogicality of "prediction of suicide" necessitates a conceptual shift in suicide risk research.

Outlook:

• Future research must employ robust methodologies that mitigate confounding by indication and protopathic bias.
• Revisiting and reinterpreting decades of prior research on suicide risk assessment tools is crucial.
• Developing valid methods to assess the true accuracy and clinical utility of suicide risk diagnostic tests is paramount.