Project Summary Older adults are at higher risk of toxicity and progressive severe effects related to cancer treatment. They experience numerous side effects from cancer treatment including chemotherapy-induced nausea and vomiting (CINV), but often undermanage it because they do not believe their actions to self-manage CINV will be effective. Many older adults report taking anti-nausea medication only when CINV is severe and some adopt a ‘watchful waiting” strategy as they wait for CINV to go away on its own. This lack of self- management leads to reduced daily functioning, reduced adherence to treatment, increased healthcare use (emergency department and hospital admissions) and cost, and lower quality of life. There is a critical need for new strategies to assist older adults in engaging in more active preventative and self-management behaviors at home to reduce negative outcomes. Our team developed and tested a serious game intervention that directly addresses older adults’ erroneous beliefs about CINV management. The eSSET-CINV intervention is a technology-based educational simulation in which older adults learn to apply what they have previously learned about CINV self- management strategies to an avatar who is at high risk for nausea at home after chemotherapy. Players make decisions to prevent CINV and to self-manage it when it occurs. Our preliminary study showed that older adults who were exposed to the eSSET-CINV intervention used twice as many CINV preventative strategies than those who did not get the intervention. The goal of this study is to determine the eSSET-CINV’s effectiveness at reducing CINV severity and healthcare use and increasing functioning and quality of life. We will use a 2-group (intervention, attention control) randomized clinical trial design. Aim 1 of this study is to examine changes in CINV severity, self- management behaviors, functioning, QOL, cognitive representation and healthcare use within the intervention group from baseline to completion of the study. Aim 2 is to determine efficacy of the eSSET-CINV intervention by comparing differences in primary outcomes (CINV severity, healthcare use) and secondary outcomes (self-management behaviors, functioning, and QOL) between groups at each follow-up visit and completion of the study. A sample of 500 older adults will be recruited. The intervention group will receive the eSSET-CINV at baseline, the attention control will receive it at the end of the study. Both groups will be followed for 6 months. Our long-term goal is to develop unique, culturally relevant serious games that allow older adults to practice making side-effect related self- care decisions at home in a no-risk simulated environment. This research addresses the NIH research priorities facilitating changes in cancer symptom prevention and self-management through increasing positive health behaviors and improved health outcomes in an understudied population.