care services contract with managed care organizations, which then select providers or groups of providers to care for an enrolled patient population. A patient either selects or is assigned a provider, typically a primary care physician who may have received special training in managing care and who may also have financial incentives to manage that care effectively. Such physicians often act as gatekeepers for access to additional specialty services because of the restrictions placed on reimbursements for specialty service provisions. Ideally, the system operates to reduce unnecessary services for health care, allowing managed care organizations to decrease their overall costs.

Theoretically, purchasers enter into contracts with managed care organizations largely on the basis of cost, the benefits package, and quality, thus creating the incentive for these organizations to offer superior services and consumer-oriented benefits. A competitive environment has produced variations in organizational structures as managed care groups attempt to balance the financial risks of cost-control measures with the provision of quality health care (Association of State and Territorial Health Officials, 1995). Managed care thus has evolved into several types of health plan structures, including health maintenance organizations (HMOs); the staff model, group model, and network model HMOs; individual practice association model and mixed model HMOs; preferred provider organizations; point-of-service plans; physician-hospital organizations; and management services organizations. Table 1-1 describes the types of managed care organizations. Appendix B is a glossary of terms and acronyms commonly used in the managed care industry and encountered throughout this workshop summary.

An effective health care delivery system depends on the availability of a continuum of different types of services, ranging from research to clinical services to public health programs. As it has evolved, managed care has influenced each of these elements of the continuum, creating new pressures, as well as providing novel opportunities. Although several areas of health care in the present system are encountering difficulties, certain aspects of managed care, primarily its emphasis on prevention, should give the public health community reasons for optimism. Some of the benefits from an emphasis on prevention include the following:

• the ability to deliver a range of clinical preventive services such as immunizations and screening for infectious diseases;

• the increase in incentives to link clinical preventive services with community-based prevention through educational outreach and behavior modification efforts;

• the data collection systems that may complement public health efforts aimed at communicable disease monitoring and quality assurance; and

• the organizational structures of managed care entities, particularly those that use selected providers and that have explicit expectations or requirements for certain clinical practices, which may prove valuable in enhancing disease reporting, disease management, and quality assurance.