PROJECT SUMMARY/ABSTRACT Patient-reported outcome measures (PROMs) are crucial for understanding the impact of cochlear implants (CIs) on real-world functional abilities and for monitoring changes over time. However, CI clinical outcome measures traditionally focus solely on CI users’ speech recognition ability, which lacks ecological validity, relies on outcomes that are weakly associated with real-world functional communication ability, and disregards important CI benefits such as improved social engagement and listening effort. Therefore, our current clinical practice standards are not evidence based due to a critical knowledge gap that limits our understanding of the broad functional impact of CIs on patients’ everyday lives. Improvement in speech recognition represents a fundamental early step in the post-CI rehabilitation process. Further lasting real-world functional improvements may occur but depend on how well CI users deploy their enhanced speech recognition skills in their everyday lives. This two-phase process emphasizes the value of combining PROMs with measures of speech recognition to comprehensively assess the patient-centered benefits of cochlear implantation. The enhanced rigor of modern PROM development methodologies, as applied in the development and validation of the new Cochlear Implant Quality of Life-35 Profile (CIQOL-35 Profile), have the potential to improve the monitoring of CI user progress and inform clinical decision making. The proposed project includes a rigorous evaluation of the benefits of CIs on a broad range of functional abilities conducted using a multi-site, longitudinal study design, which will provide, for the first time, a comprehensive understanding of outcomes meaningful to patients and accomplish the following Aims. Aim 1 will apply a novel CIQOL functional staging system, which provides real-world context to CIQOL scores while maintaining the hierarchy of quantitative scores, in a group-based trajectory model to identify clusters of patients in the longitudinal study who follow similar progressions through the CIQOL functional staging system and identify patient factors associated with each trajectory cluster. Aim 2 will first determine the magnitude of change in CIQOL-35 Profile scores considered clinically meaningful to CI users, then apply these findings to better understand the association between early meaningful improvement after implantation and long- term functional outcomes. Specifically, we aim to promptly identify patients at risk of poorer long-term outcomes who may benefit from additional resources. Finally, Aim 3 will apply an implementation science approach to translate the findings from our longitudinal study into clinical practice and enhance the integration of CIQOL instruments into routine CI care. Together, the proposed research program will enhance the interpretation and application of real-world CI outcomes for individual patients, inform patient discussions regarding expected r...