Infection control and changing health-care delivery systems.

In the past, health care was delivered mainly in acute-care facilities. Today, health care is delivered in hospital, outpatient, transitional care, long-term care, rehabilitative care, home, and private office settings. Measures to reduce health-care costs include decreasing the number of hospitals and the length of patient stays, increasing outpatient and home care, and increasing long-term care for the elderly. The home-care industry and managed care have become major providers of health care. The role of specialists in health-care epidemiology has changed accordingly.