Managed Care, Information, and Diffusion: The Case of Treatment for Heart Attack Patients

Growth in the size and power of managed-care organizations seems to have had widespread effects on the health-care system. Not only may health maintenance organizations (HMOs) and other forms of managed care influence the care provided to the patients that they cover, but the activities of these organizations may also bring about broader changes in the delivery of health care. Such “spillover effects” of managed care could ultimately affect even health care for patients who have not joined managed-care organizations. While previous literature on the relationship between area HMO market share and spending is consistent with the presence of spillover effects (e.g. Baker, 1999), few studies have examined treatment patterns directly (e.g. Heidenreich et al., 2002). Nevertheless, the potential for changes in patient care are of central importance for gaining a full understanding of the overall effects of managed care on the health care system. (May 2004)