Lesson 2: Surveillance Systems
According to the Centers for Disease Control and Prevention (2009c), public health surveillance encompasses data collection for infectious and chronic diseases, injuries, environmental and occupational exposures, and personal behaviors that promote health and prevent disease.
The techniques used in public health surveillance are not disease-specific; they can be applied to gather data about a variety of health conditions, exposures, and behaviors of concern to public health agencies. Public health surveillance is based on a simple premise: understanding a problem is essential to solving it.
The CDC (2009c) defines surveillance as the “ ongoing, systematic collection, analysis, and interpretation of health data essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely feedback of these data to those who need to know. ” Analysis of surveillance data often begins by summarizing it according to event or problem, person, place, and time — that is, looking for patterns of disease or health outcomes among different populations, in different places, at different times.
Identifying who got sick, where they went prior to becoming sick and while sick, and when and for what duration they were sick, yields valuable information about the types of disease control and prevention efforts that are needed and the people who need to be targeted in order to most efficiently limit or prevent the spread of disease.
Examining surveillance data focused on health promotion and disease prevention behaviors for trends is as important as focusing on the disease and injury occurrences themselves. For example, knowing the patterns of vaccination coverage helps us understand why cases of vaccine-preventable diseases are declining, and knowing
Consider that in 1900 in the United States, the leading killer was a communicable
disease (tuberculosis), whereas in 2010, the leading killer will be a disease usually
caused by health behaviors that can be prevented (heart disease). McGinnis and Foege
(1993) took these data one step further and determined that the real causes of most
heart disease are tobacco use, poor diet, excess weight, and physical inactivity. With
this revelation, the country was ready to use epidemiology to develop health promotion
programs to educate people to prevent chronic diseases.
Furthermore, life expectancy in 1900 was only forty – nine years of age; that figure has now increased by almost thirty years. This increase in life expectancy is due in large part not to better medical care but to a better understanding of how disease occurs and how to prevent it. As a result of learning the real causes of disease, medicine has started to shift its emphasis from curing individuals to preventing illness and disease.
Dever (2006) argues that of the methods of epidemiology being made available through surveillance data, one of the most important is the concept of risk analysis.
Using the parameters of high-risk health behaviors, we are better able to understand the major diseases of today and predict the major diseases of the future. We can also better understand and learn how to prevent workplace injuries and illnesses. Levy, Wagner, Rest, and Weeks (2005) found that information from good surveillance systems can be used to detect trends, clusters, associations, and causes of disease and injuries and is one of the answers to reducing morbidity and mortality in the workplace.