This project is part of AcademyHealth’s efforts to better understand and address disparities in diagnosis with funding from the Gordon and Betty Moore Foundation. The goal of this project is to develop interventions that support vulnerable patients, families and clinicians to improve timely, effective, and equitable diagnosis and its burdens. Missed and delayed diagnoses are especially common and dangerous in oncology, where indolent diseases produce subtle signs and symptoms that may be difficult to detect and assess. Existing research suggests that patient factors, such as patients’ willingness or ability to engage with the health care system or complete recommended referrals, tests, and treatments, may play a particularly significant role in the diagnosis of cancer among minority and marginalized individuals and communities. Hence, assuring timely and accurate cancer diagnoses for these populations requires an understanding of both the clinical diagnostic process and the complex reality of patients’ diagnostic experiences. Using data abstracted from patients’ electronic health records for a retrospective cohort of 250 breast cancer patients diagnosed at the Tufts Medicine cancer center, the research team will conduct logistic regressions to identify clinical and socioeconomic factors associated with diagnostic delays of more than 90 days from symptom onset or abnormal screening test to confirmed diagnosis. Through in-depth chart reviews and interviews with a subset of 30 patients, they will develop detailed process maps and patient journey maps of patients’ experiences of care. The research team will then use qualitative research methods to analyze the patient journey maps to identify potential interventions for reducing diagnostic inequity at specific points in the diagnostic process. Deliverables will include a project work plan, narrative and financial reports, and a range of products to reach clinicians, policymakers and other audiences with study findings.