In recent years, significant efforts have been made to improve the definition and measurement of the Essential Public Health Functions. It is important to consider the following evolution of the EPHF in order to understand the concepts presented here:

• In 1988, after more than sixty years of efforts to define and measure the performance of the public health functions, the Institute of Medicine of the United States (IOM) published The Future of Public Health.  This book identified three basic functions of the public health agencies at all levels of government: evaluation, policymaking, and safety.

- Evaluation includes a systematic monitoring of health status and the needs of the community. 
- Policymaking refers to the responsibility of the public health agencies to prepare broad policies based on the available information concerning the community’s health needs.
- Finally, safety refers to the guaranteed delivery of community health services offered by the government.

• In 1994, the then Director of the Centers for Disease Control and Prevention (CDC ), David Satcher, and the Adjunct Secretary for Disease Prevention and Health Promotion, Dr. J. Michael McGinnis, created a working group on the basic functions of public health with fellow representatives of public health agencies and organizations. The group’s primary task was to eliminate the confusion surrounding various versions of the “essential” health functions. The group produced a consensus statement entitled “Essential Services of Public Health”, which identified the vision of public health as healthy people living in healthy communities and the mission of public health as promoting physical and mental health while preventing disease, injury, and disability.

• That same year, the Public Health Functions Steering Committee released the document “Public Health in the United States of America” in which public health’s vision and mission were based on the following main objectives:

• Prevention of epidemics and the spread of disease
• Protection against environmental threats
• Prevention of health impairments
• Promotion of healthy behaviors
• Response to disasters and assistance to affected communities
• Quality assurance and access to health services

• This document also defines ten essential public health services as follows:

• Monitoring the health situation to identify community health problems
• Diagnosing and researching the community’s health problems and risks
• Informing, educating, and empowering the public in health subjects
• Mobilization of community organizations to identify and solve health problems
• Development of policies and plans to support both individual and public health
• Fulfillment of laws and regulations to protect health and provide safety
• Linking people to health care services to guarantee the delivery of health services where they are not available
• Guaranteeing competent human resources for public health and health care
• Evaluating the efficacy, accessibility, and quality of individual and public health care services
• Researching new approaches and innovative solutions to health problems

• In January of 1997, the Executive Committee of WHO recommended the conceptual development of the Essential Public Health Functions in support of the Health for All in 2000 program renewal.  To achieve this goal, the Delphi methodology was employed through a series of questionnaires sent to a pre-selected group of experts.  Using this surveying technique, an international study was conducted to: (i) redefine the EPHF concept; (ii) establish an international consensus on the central characteristics and capabilities of the EPHF; (iii) determine which public health functions are likely to become essential in the future; and (iv) identify which public health functions require the development of performance standards.  For this study, 145 public health experts of different nationalities were consulted at three consecutive meetings. 

The panel was finally able to identify nine EPHF:

1. Monitoring the health situation
2. Environmental protection
3. Health promotion
4. Prevention, surveillance, and control of communicable and non-communicable diseases
5. Public health legislation and regulation
6. Occupational health
7. Specific public health services
8. Health management and administration
9. Health care for vulnerable groups and high-risk populations

• In 1999, PAHO/WHO in collaboration with the CDC and the Latin American Center for Research in the Health Sciences (CLAISS) launched the Public Health in the Americas Initiative. Based on the list of public health functions identified in the 1998 PAHO/WHO document entitled “Essential Functions of Public Health: A Position Paper,” as well as the eleven essential services defined by the CDC’s work group and the nine EPHF delineated by the WHO’s Delphi study, PAHO developed the first draft of the twelve public health functions and a methodology to measure their performance.

This instrument was pilot-tested in Colombia, Jamaica, and Bolivia. The results of these experiments were then used to reach a consensus on the eleven EPHF currently in use today.