DESCRIPTION OF THE PROJECT: The goal of the Translating Research into Action for Diabetes (TRIAD) legacy studies is to examine the system- and patient-level factors that are associated with long-term processes of care, morbidity, costs, and mortality of persons with diabetes. To address this goal this Legacy Study application proposes five specific aims. The first aim will generate two reports from the multi-site TRIAD cohort that was recruited in 2001 and the remaining aims will extend our work on the TRIAD Part D Medicare Study with 4 new reports that will analyze recently acquired 2007 claims data from 50 states from one of the largest providers of the Part D benefit in the nation. Our specific aims are: 1) To examine whether there is an association between depression and under-use of medications for depression with medical costs and mortality for persons in the TRIAD cohort; 2) To use 2007 data from Medicare Advantage Part D (MAPD) beneficiaries who reside in 50 states to examine the role of chronic medical conditions such as diabetes, dementia, and depression on out-of-pocket costs, gap entry and adherence to medications; 3) To determine the potential cost savings in the Medicare Part D program from generic and therapeutic substitution using data from a 50-state sample of MAPD beneficiaries collected in 2007; 4) To examine the impact of mail-order use on out-of-pocket costs, total medication costs, and medication adherence for the poorest Medicare beneficiaries with diabetes in the Part D program; 5) To compare the out-of-pocket medication costs, total drug costs, and adherence to chronic medications for beneficiaries in Low Income Qualifier (LIQ) versus commercial plans and for persons with diabetes. Many of the reports that either have UCLA faculty as first or senior author have focused on studying underserved and/or high risk populations with diabetes. During the Legacy Study, the 6 analyses proposed will continue to emphasize how benefit design, cost sharing, and co-morbidities such as depression may disproportionately affect the most vulnerable persons with diabetes. A second objective of the Legacy Study is to continue to develop emerging investigators. To this end, the proposed team will continue our 11-year track record of successful mentorship and advancement of junior investigators with a strong focus on women and minority investigators by continuing to mentor Dr. O. Kenrik Duru, Assistant Professor at UCLA, and Rui Li, Ph.D., an economist at the CDC who has recently joined our team and will continue to work with us during the proposed Legacy where she will be mentored by Dr. Susan Ettner, our senior health economist, and Dr. Carol Mangione, the principal investigator of the UCLA Translational Research Center (TRC). Additionally, we expect to continue our mentoring relationships with a number of investigators from the other TRIAD TRCs. Finally, during the TRIAD Legacy phase we expect to be full participants in the steering and publication committee activities that will be vital to the success of the final stage of this ground-breaking study.