Background: Prevalence of moderate to severe chronic kidney disease (CKD) is 70% higher in veterans than the general population. Annual cost for non-dialysis dependent CKD population care increased to $18 billion in FY 2016 for Veterans Administration. Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARBs) are considered standard of care for CKD patients as they improve cardiovascular outcomes and retard progression to end stage kidney disease. Among veterans with diabetes and CKD, only 66% are on ACEI or ARB with significant variation across facilities. Among the ~34% not receiving ACEI or ARB, it is unclear whether they were started on these agents, started but stopped due to an adverse event or never started on ACEI or ARBs for e.g. due to clinical inertia. ACEI/ARB discontinuation is associated with an increased need for dialysis and a higher risk of mortality. In this proposal, we plan to understand the proportion of underuse of ACEI/ARB attributed to side effects versus clinical inertia using structured datasets and unstructured provider text notes, and barriers to initiation and re-initiation (after being discontinued) of ACEI/ARB. Based on these learnings, we propose to pilot test a communication aid in patient aligned care teams (PACTs), which will assist clinicians to initiate or reinitiate ACEI/ARB therapy in CKD patients. Significance: Successful implementation of the proposed study will help us (a) understand the reasons for lack of initiation of ACEI or ARB and their discontinuation (b) successfully develop, refine and pilot test a communication aid to optimize ACEI/ARB use among CKD population. These could reduce kidney disease progression, an improvement in cardiovascular outcomes and potential cost savings for the VA system. Innovation: The project utilizes both structured and unstructured data using natural language processing (NLP) to understand the full context for underutilization of ACEI or ARBS. Furthermore, we utilize innovative qualitative techniques and human factors bests practices to study and address this important gap in care. Aim 1: To examine reasons for lack of initiation and discontinuation of ACEI or ARBs among CKD patients based on structured data and automated information extraction using NLP. Aim 2: To conduct semi-structured interviews with PACT providers and patients at two tertiary care facilities and their community-based outpatient clinics (CBOCs) to further understand the reasons for lack of initiation or discontinuation of ACEI or ARBs among veterans with CKD. Based on these interviews, we will refine a succinct communication aid targeted towards PACT providers which will allow them to effectively initiate and/or reinitiate ACEI/ARB in CKD patients (including those with prior side effects). Aim3: To pilot test a communication aid for clinicians to improve initiation of ACEI or ARB or re-initiation of ACEI or ARB after being discontinued due to an adverse event. Meth...