OBJECTIVE: This study sought to determine whether demographic and clinical factors for suicidal ideation (SI) and suicide attempts (SA) in adults vary across different census divisions in the US. METHODS: A nationwide cohort was constructed using commercial health insurance claims data of adults aged 25-64 years with at least one mental health or substance use disorder-related outpatient visit between 2014 and 2015. Survival analysis was used to study how the association of demographic and clinical factors on SI and SA vary by geographic divisions. RESULTS: The Mountain Division had the highest rates of SI and SA in almost all observed time intervals after the index visit. The Northeast region and the West coast had the lowest rates. For both SI and SA, we observed strong interaction effects between geographic division and urbanicity (χ2(152) = 188.14, p = 0.02
χ2(152) = 196.20, p = 0.01, respectively). In particular, urbanicity was a risk factor for SI in the West North Central (HR = 0.71, 95% CI: [0.50, 0.99]) and the Pacific (HR = 0.54, 95% CI: [0.40, 0.74]) Divisions. Urbanicity was also a risk factor for SA in the West North Central Division (HR = 0.39, 95% CI: [0.16, 0.95]), but a protective factor for SA in the Mountain Division (HR = 1.71, 95% CI: [1.11, 2.63]). CONCLUSIONS: The association between urbanicity and SI and SA varied by US geography. Future suicide prevention efforts should include a focus on urban adults in the West North Central and the Pacific Divisions, and rural adults in the Mountain Division.