The PHL is a central part of the public health infrastructure. PHLs support the public health infrastructure in each of the three core public health functions. Descriptions of PHL activities within these core functions have been previously described by the CDC and the ASTPHLD:3, 4, 5
- Assessment -- includes laboratory testing for infectious diseases, reference testing related to exotic diseases, and highly specialized esoteric tests. PHLs often perform tests unrelated to individual treatment but significant for public health reasons, (e.g., serotyping of bacteria). Other assessment measures include gathering of test results, documentation of food- and water-borne infection, environmental testing, and research. Epidemiologic work by public health agencies is often dependent on PHL testing and analysis of specimens received from private providers, public health clinics, hospitals, and even private laboratories.
- Policy Development -- includes consulting in technology, testing, and research needs for program and policy development on health issues such as HIV/AIDS, sexually transmitted diseases (STDs), and tuberculosis. PHLs can play a role in environmental health policy by identifying health hazards through testing and developing policies to solve environmental problems. In some states, PHLs are responsible for developing and implementing regulations (e.g., CLIA ' 88) regarding operation of private laboratories in the state.
- Assurance -- includes providing patient testing for indigent populations and persons unable to afford tests. State PHLs generally provide newborn genetic screening for state residents, laboratory personnel / facilities licensure, laboratory personnel training, and environmental monitoring. In addition, PHLs have a role in assurance through measuring the effectiveness of intervention programs.
PHLs differ dramatically in both structure and range of services. All fifty states and the District of Columbia operate their own state PHL.6 Generally, the state PHL operates under the leadership of the state health officer; however, the nature of the relationship between the health officer and the laboratory director varies by state.4 For example, in Oregon, the Center for Public Health Laboratories is one of the five main centers in the Oregon Health Division, and the laboratory director is an Assistant Administrator of the Health Division. In Tennessee, the Division of Laboratory Services is a unit directly under the supervision of the Commissioner of the Tennessee Department of Health. In contrast to these separate laboratory service divisions, Washington State has combined its laboratory services and epidemiology section into a central office called Epidemiology, Health Statistics and Public Health Laboratories; this office is one of the five main bureaus of the Washington Department of Health.
The size of state PHLs in terms of both staffing and funding varies by state. For instance, in fiscal year 1996, the Tennessee State PHL had a staff of 186 full-time equivalents (FTEs) and a budget of $9.5 million; Wisconsin's state PHL had 280 FTEs with a budget of $23 million; and Florida's state PHL had a statewide staff of 354 FTEs and a budget of $21 million (1995-96 budget). The revenue streams of state PHLs also vary in the proportion of funding that comes from federal, state, and other sources. For example, the Michigan and Wisconsin State PHLs receive 60 to 70 percent of their funding from state and federal sources and the remaining funding directly from generation of user fees. In comparison, the Tennessee State PHL receives 95 percent of its funding directly from the state; it collects fees for certain services, but the state PHL passes all revenues through to the general state administration.
Many states also operate regional laboratories that perform certain tests and act as liaisons for sending other samples to the central state laboratory. For instance, both Maryland and Tennessee operate four regional laboratories within their respective states. Regional laboratories may be full service extensions of the central state laboratory or smaller outposts. For example, one of the regional laboratories in Tennessee has a small staff of two FTEs and performs microbiology tests exclusively. In contrast, other states, such as Oregon and Wyoming, operate only one centrally located state public health laboratory.
One major difference among state PHLs is the extent to which state laboratories devote resources to direct patient testing for personal health services versus testing for population-based screening and surveillance. New York's PHL is called the Wadsworth Center, and it devotes one-third of its resources to the laboratory licensure program for private laboratories; one-third of its resources operating as a large basic grant funded research entity; and one-third of its resources for administration, testing, and environmental health monitoring. Other states like Tennessee have traditionally performed direct tests of patient specimens received from local health departments and other public health agencies.
The variations in functions and structures of state PHLs have a direct effect on how laboratories define their role in the public health infrastructure and how current market changes will affect the laboratories themselves. Some state PHLs that have traditionally performed tests for indigent patients seeking care in local health departments have noted that the number of specimens they receive is decreasing as states expand Medicaid managed care programs. In fact, private managed care companies that bid for and receive approval to enroll Medicaid clients often contract with large private laboratories for some or all clinical testing services. Therefore, many of the Medicaid and other indigent patients traditionally treated by local health departments are entering managed care plans where their tests are sent to private laboratories. Consequently, the state also may receive fewer samples for surveillance purposes.
In recent years, the public health community has tried to identify its role and responsibilities at all levels of government. Health care market changes, such as increased managed care penetration, hospital and other health system consolidation, and privatization, have stimulated public health agencies to review their community role and goals. Consolidation in the private laboratory market and increased managed care presence in serving Medicaid populations threaten to impose major changes on the way in which PHLs have traditionally served communities.