children. Public financing, primarily through the Medicaid program, provides a higher proportion of revenues for the specialty and rehabilitation hospitals than for hospitals that provide acute care (Figure 4.4).

Most of the data in this section were collected by the National Association of Children's Hospitals and Related Institutions (NACHRI) and come from freestanding children's hospitals, which have their own administrative and financial reporting systems. (Data for pediatric patients from nonfreestanding units are not readily available.) Freestanding acute care children's hospitals make up only 1 percent of all hospitals in the United States, but they deliver 18 percent of inpatient days of care for children who need to be hospitalized. In 1993, they provided 3.2 million days of inpatient care at a cost of more than $7 billion, along with more than 8.3 million visits to outpatient clinics (Gage et al., 1995).

Because the developmental needs of children are better served by fewer overnight visits, outpatient and ambulatory visits are increasing as alternatives to inpatient care (Table 4.5). The increases in revenue for inpatient and outpatient care are comparable (Figure 4.5). The data also indicate that as the proportion of Medicaid patients is increasing, the proportion of uninsured patients is decreasing (Table 4.5).

Another trend for children's hospitals is the growth in regionalized pediatric medical specialty centers, or centers of excellence. Patients from a large metropolitan area, from a multi-state region, or from all over the country may be referred to these centers. A high percentage of the hospitalized children are those with chronic health problems and special health care needs such as cystic fibrosis, cerebral palsy, HIV infection, or other conditions. According to data from NACHRI, 70 to 80 percent of the hospitalizations for complex children's health conditions take place in children's hospitals or general hospitals with pediatric residency programs, which together make up only 5 percent of the total hospitals nationwide (Neff and Anderson, 1995).

In 1989, in its report entitled The Future of Public Health, the Institute of Medicine (IOM) defined the mission of public health as ''fulfilling society's interest in assuring conditions in which people can be healthy" (IOM, 1989, p. 7). The IOM report described the core responsibilities of public agencies as protecting the nation's health through the application of scientific and technical knowledge to prevent disease and to promote health. Public health agencies thus have responsibilities for the assessment, monitoring, and surveillance of health problems; for collecting information that can be used to direct resources to areas of need; and for designing and implementing programs that will improve the health of the public (IOM, 1989, 1997).