PROJECT SUMMARY/ABSTRACT The national Zero Suicide initiative considers all suicide deaths in healthcare settings to be preventable. Research about suicide in nursing homes is necessary given residents’ elevated risk for suicide, the growing importance of this setting as the population ages, and the lack of research on this topic. We propose leveraging our integrated nursing home database of the Minimum Data Set (MDS) 3.0, Medicare eligibility and claims (Part A, B & D) and the Certification and Survey Provider Enhanced Reporting system to examine suicidal ideation and attempts among nursing home residents. Doing so will provide a rare opportunity to use resident- and facility-level data to examine transdiagnostic patterns of risk and protective factors for suicide- related outcomes among a vulnerable population. No national studies have attempted to characterize patterns of risk and protective factors for suicidal ideation and suicide attempts among nursing home residents. The specific aims are to: 1) estimate the prevalence of ideation and attempts during the nursing home stay; 2) identify resident and facility characteristics associated with ideation and attempts; 3) identify and describe distinct subgroups of latent suicide risk among nursing home residents at admission; 4) examine changes in residents’ latent suicide risk throughout the nursing home stay; and 5) identify predictors of change in suicide risk throughout the nursing home stay. Multilevel latent variable models will allow us to identify subgroups of suicide risk and characterize the trajectories of patterns of suicide risk factors and outcomes throughout the nursing home stay. The proposed research responds to the call for research on trajectories of suicide risk to inform how and when to intervene (NIMH Strategic Priority 2) as well as the National Action Alliance for Suicide Prevention Research Prioritization Task Force call for the use of existing data sources such as MDS 3.0 to understand suicide risk in healthcare settings. The proposed work will provide knowledge necessary to ultimately help improve efforts to identify nursing home residents at high risk for suicide and inform tailored suicide prevention efforts in this healthcare setting. The results will also inform future research efforts aimed at improving methods of understanding individuals’ suicide risk throughout lengths of stays in nursing facilities.