The long-term goal of this work is to improve centralized pain management in older adults. Pain may be categorized as neuropathic, nociceptive, or nociplastic (i.e., centralized). Management of these pains should differ based on their etiology. Medications should be chosen that target this (Mechanistic-Based Pain Therapy, MBPT). Patient outcomes in other populations have improved when MBPT has been used. The objective of this work is to understand medication use in older adult cancer survivors with centralized pain, focusing on provider decision-making and practice patterns. This knowledge is fundamental to the creation of a clinical decision support system. With the growing population of older adult cancer survivors and the risks of medications (Potentially Inappropriate Medications, PIMs), there is a critical need to improve the appropriate use of medications to manage centralized pain. Survivorship guidelines provide no direction specific to older adults or centralized pain. Our central hypothesis is that centralized pain experienced by older adult cancer survivors will vary by age in terms of diagnoses, MBPT, and PIM use. To test this hypothesis an explanatory sequential mixed methods design was developed with the following aims to meet the stated objectives: Aim 1: Determine the effect of age on developing centralized pain among older adult cancer survivors in the U.S. before and after cancer diagnosis. H1: Increasing age will be related to greater likelihood of centralized pain before and after cancer diagnosis. This quantitative aim will utilize newly validated methods34,35 to estimate the effect of age independent of other predictors on developing centralized pain among cancer survivors ≥ 66 years of age who are diagnosed with centralized pain before and after cancer diagnosis using the SEER-Medicare database. This aim will provide training related to large datasets and responsible conduct of research (RCR) using secondary data. Aim 2: Quantify effect of MBPT on PIM use among older adult cancer survivors with centralized pain. H2: Higher MBPT will be correlated with lower PIM use among older adult cancer survivors. This quantitative aim will innovatively advance the previous methods34,35 using centralized pain diagnosis codes to determine MBPT and PIM prevalence by matching medication claims to diagnoses. This aim will provide training related to pain pathophysiology, treatment of centralized pain, and large dataset management. Aim 3: Identify facilitators/barriers to centralized pain management in older adult cancer survivors. This integrative aim will use interviews of oncologists, geriatricians, and PCPs (n~30) (qualitative) in combination with prescribing profiles of participants (quantitative) to characterize centralized pain management using a theoretical framework.36 Independent intramethod analysis and explanatory integration will be used to understand centralized pain management in older adult cancer survivors. This aim will prov...