Patients often see multiple health professionals in a variety of places for the care of their health problems. Linking care from different providers over time is challenging, with the risk that some care may be missed, duplicated or ill-timed. Concern about this fragmentation of care is growing in Canada and worldwide. Continuity of care, which is accomplished when the connections between care are seamless, is thought to improve patient outcomes, patient satisfaction with their care and physician and health providers' satisfaction as well. I am studying the impact of continuity of care on costs and quality of care. A common way to connect care over time is to have one central person, usually a primary care physician, responsible for providing the majority of services and linking a patient to specialists. I am examining a variety of data to measure the concentration of care in this type of sustained relationship. A growing trend is team care provided at a clinic, where patients see any one of the physicians working there. My study will compare outcomes for patients who use health care teams to those who primarily see one physician, and I will look at the way walk-in clinic care affects continuity and patient outcomes. I will also examine how continuity of care affects patient health over time for people with severe and persistent mental illness, individuals with workplace injuries, and patients with HIV/AIDS.