A Quasi-Experimental Analysis of Lethal Means Assessment and Risk for Subsequent Suicide Attempts and Deaths

Background Counseling on access to lethal means is highly recommended for patients with suicide risk, but there are no formal evaluations of its impact in real-world settings. Objective Evaluate whether lethal means assessment reduces the likelihood of suicide attempt and death outcomes. Design Quasi-experimental design using an instrumental variable to overcome confounding due to unmeasured patient characteristics that could influence provider decisions to deliver lethal means assessment. Setting Kaiser Permanente Colorado, an integrated health system serving over 600,000 members, with comprehensive capture of all electronic health records, medical claims, and death information. Participants Adult patients who endorsed suicide ideation on the Patient Health Questionnaire-9 (PHQ-9) depression screener administered in behavioral health and primary care settings from 2010 to 2016. Interventions Provider documentation of lethal means assessment in the text of clinical notes, collected using a validated Natural Language Processing program. Measurements Main outcome was ICD-9 or ICD-10 codes for self-inflicted injury or suicide death within 180 days of index PHQ-9 event. Results We found 33% of patients with suicide ideation reported on the PHQ-9 received lethal means assessment in the 30 days following identification. Lethal means assessment reduced the risk of a suicide attempt or death within 180 days from 3.3 to 0.83% (p = .034, 95% CI = .069-.9). Limitations Unmeasured suicide prevention practices that co-occur with lethal means assessment may contribute to the effects observed. Conclusions Clinicians should expand the use of counseling on access to lethal means, along with co-occurring suicide prevention practices, to all patients who report suicide ideation.