Accuracy of ICD-10 codes for suicidal ideation and action in pediatric emergency department encounters.

Objectives: According to the ideation-to-action framework of suicidality, suicidal ideation and suicidal action arise via distinct trajectories. Studying suicidality under this framework requires accurate identification of both ideation and action. We sought to assess the accuracy of ICD-10 codes for suicidal ideation and action in emergency department (ED) encounters. Methods: Accuracy of ICD-10 coding for suicidality was assessed through chart review of clinical notes for 205 ED encounters among patients 6-18 years old at a large academic pediatric hospital between June 1, 2016, and June 1, 2022. Physician notes were reviewed for documentation of past or present suicidal ideation, suicidal action, or both. The study cohort consisted of 103 randomly selected "cases," or encounters assigned at least one ICD-10 code for suicidality, and 102 propensity-matched "non-cases" lacking ICD-10 codes. Accuracy of ICD-10 codes was assessed using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: Against a gold standard chart review, the PPV for ICD-10 suicidality codes was 86.9%, and the NPV was 76.2%. Nearly half of encounters involving suicidality were not captured by ICD-10 coding (sensitivity=53.4%). Sensitivity was higher for ideation-present (82.4%) than for action-present (33.7%) or action-past (20.4%). Conclusions: Many cases of suicidality may be missed by relying on only ICD-10 codes. Accuracy of ICD-10 codes is high for suicidal ideation but low for action. To scale the ideation-to-action model for use in large populations, better data sources are needed to identify cases of suicidal action.