What is Public Health?

An Orientation for HIE Leaders

"Public health" is a complex concept, defined broadly as "what society does collectively to assure the conditions for people to be healthy." Healthcare providers, businesses, schools, non-profit organizations and other government agencies all contribute to the public health of a community.

In the United States, a "health department" is a government agency that oversees public health in a state or local jurisdiction (including U.S. Territories). Health department functions now go beyond enforcing sanitary codes and delivering direct services, to encouraging and coordinating various public and private activities that promote and protect health in their jurisdictions.

Although health departments once provided much healthcare for the indigent, community health centers and publicly-funded insurance (such as Medicaid and the Affordable Care Act insurance exchange subsidies) have largely replaced this role in many communities.

Public Health and HIE Case Studies

The following case studies, which are referenced later in this toolkit, offer useful examples of collaborative efforts between public health and HIE:

Because the U.S. Constitution reserved "police powers" (including public health) for states rather than the federal government, there is considerable variation in which services are offered and how they are organized. In some states, public health authority and budgets are centralized at the state level; in others, these are subject to "home rule" by counties, villages and cities.

While the federal government has direct control over public health in limited domains like inter-state commerce, much of its influence on state and local public health departments is based on funding, research and consensus building. One consequence of this is that most "national" public health information systems are actually built from somewhat independent state-level systems. This partly decentralized approach led to the creation of national public health information exchange (PHIN) standards, some of which were incorporated into the EHR Incentive Program (Meaningful Use) specifications.

Many public health information systems are operated at the state level, such as communicable disease reporting, immunization information systems, syndromic surveillance systems and cancer registries. Like HIOs, however, some of these also developed and remain active at local or regional sub-state levels.

Core Functions

Emerging consensus identifies three core functions and services for any public health jurisdiction:

  1. Assessment of population health and risks
  2. Assurance of necessary services
  3. Policy-making for a healthier environment and population

Essential Services

Essential public health services include:

  • Monitoring public health status to identify and solve community health problems
  • Diagnosing and investigating health problems and potential hazards in the community
  • Informing, educating and empowering people about health issues
  • Mobilizing community partnerships and action to identify and solve health problems
  • Developing policies and plans that support individual and community health efforts
  • Enforcing laws and regulations that protect health and ensure safety
  • Linking people to needed personal health services and assuring the provision of healthcare when otherwise unattainable
  • Assuring a competent public and personal healthcare workforce
  • Evaluting effectiveness, accessibility and quality of personal and population-based health services
  • Researching for new insights and innovative solutions to health problems


A national system for voluntary accreditation of local and state health departments, based on these key functions and services, was recently implemented by the Public Health Accreditation Board.

There are many areas of potential overlap between health departments and most HIOs. Health departments have been an important voice in the evolution of early HIOs, and continue to play several key roles in the development of HIE services and use cases.


Given their roles in monitoring health, mobilizing partnerships and improving health services, local and state health departments are often important facilitators for HIOs. They bring two key advantages to the process:

  1. They can play the role of neutral convener among healthcare providers who are in competition with one another.
  2. Public health grants can sometimes provide implementation funding for certain exchange use cases.

Information Users

Health departments are core information users. Examples of the types of information used include the standardized reports listed among the Population and Public Health Meaningful Use objectives of the EHR Incentive Program, such as:

  • Laboratory results for reportable illnesses;
  • Syndromic surveillance of healthcare utilization for various symptom complexes;
  • Immunization events to populate immunization information systems; and
  • Reports of cancer incidence and treatment through cancer registries.

In some jurisdictions, HIOs are critical suppliers of this type of information reporting (see Case Study #1 for an example). Some health departments are creating community-level registries to support coordinated clinical and community management of health risks, like obesity or asthma (see Case Study #2). Some are even participating in efforts to leverage HIE to support public health nurse support for diabetes care, school nurse participation in asthma care plans, and to enhance information availability for EMS professionals, all in non-medical settings (see Case Study #3).

Information Contributors

Health departments are also important information contributors. Some offer laboratory and diagnostic services, and many still provide clinical services - ranging from immunizations and comprehensive primary care to home health services - without which a community health record would be incomplete. Health departments may also provide substantial immunization information, information about community health resources, alerts about outbreaks and other emergencies, decision support tools and other information valuable to other HIE users.

Transformers of Healthcare

Finally many health departments play a critical role in the transformation of healthcare in communities. In this role, they may work with HIOs in developing use cases to achieve:

  • better multi-disciplinary or multi-organizational team care;
  • better healthcare access, navigation and coordination; and
  • linking patients with community-based services.

Unfortunately, it is difficult to generalize about health departments, given the variability in their programs, authority, leadership and informatics competency. An HIO needs to get to know the unique constellation of assets and needs of the state and local health departments within its service area.

Continue to Next Page: What is Health Information Exchange?

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A PDF of the complete Toolkit can be downloaded on the Public Health & HIE Toolkit Downloads page.  The PDF includes illustrations, footnotes and references not visible using the web version.  Individual tools and reference materials can also be downloaded from the Downloads page.

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