1) The document describes two case studies of surveys conducted to gather evidence on patient experiences with leukemia. The Living with Leukemia survey contacted over 2,300 leukemia patients and published results on their needs and journey. 2) The Acute Leukemia Global Quality of Life Survey was conducted across 10+ languages to identify quality of life issues for patients with acute leukemia. It tested hypotheses about factors impacting quality of life. 3) The document then provides guidance on how to use evidence gathered from such surveys for advocacy impact. It discusses using evidence to define unmet needs, inform strategy, develop new services, run awareness campaigns, and engage in health technology assessments and regulatory processes.