A rise in chronic conditions has put a strain on our healthcare system. Treatment for chronic conditions spans time, agencies, and providers, making coordination a complex problem. Information systems such as electronic health records should be helping with the challenge of coordination, but research shows that often they do not. This thesis aims to alleviate this problem by examining the design of health information technology with an emphasis on social and organizational processes. The focus of this thesis is on the implications of continuous care over time: the shift from a single provider to team-based services, the emergence of patients and families as primary caregivers in the home, and the diffusion of data-driven decision making. I investigated these trends to understand the role of data in coordinating long-term care, and inform the design of information systems.I studied behavioral and mental health services for children, which are coordinated across clinical, home, and special education settings. I found coordination that was unstructured, unpredictable, and adaptive.I developed a conceptual framework, collaborative reflection, to describe my observations and distinguish my findings from the processes of time-critical and protocol-based care. I also found ways in which coordination was not data-driven, due to a lack of support and tools. Collaborative reflection thus illustrates how long-term coordination works when it is data-driven, informing a discussion of what is needed for coordination to be data-driven.Based on the process of collaborative reflection, and using participatory design, I developed Lilypad-a tablet-based information system for data-driven coordination. I conducted a five-month deployment study of Lilypad in the field, to examine its social impact. This study validated designing for collaborative reflection to improve the use of data in coordination.The contributions of this thesis are: a description of unstructured and informal workflow that drives long-term coordination in health services; the theoretical construct of collaborative reflection to inform the design of systems that improve coordination; a field deployment validation, demonstrating how designing for collaborative reflection improves coordination and avoids common unintended consequences of health information technology. My committee shared in my passion for this work, and pushed me to honor the vision I had for it. JillLehman helped me learn to be thoughtful and conscientious in my research, so I can realize my dream of creating technology that will truly have a positive impact on the world. Mary Czerwinski jumped into this with enthusiasm and encouragement, and provided positivity during a process that is all about critique. Madhu Reddy wasted no time putting his mark on this work with lasting influence, believing in me from the moment we met, and being a wonderful mentor during the critical juncture that is transitioning out of being a PhD student. This work was accomplished by an impeccable team, which enab...