What is Public Health?
Public health has provided enormous benefits to many populations, particularly in the developed world. Ironically, the general public is largely unaware of what public health is and what its functions are, partly because of the complexity of disease causation, and partly because, when public health is successful, health problems are prevented. The life of a person who develops severe heart disease might be prolonged by a dramatic and very expensive medical procedure such as heart surgery. However, public health is about interventions that prevent disease from occurring, so the benefits tend to be less obvious. In addition, prevention of disease both prolongs life and improves the quality of life. In a sense, public health is the heart disease that never developed, the epidemic that didn't happen, the outbreak of foodborne illness that never occurred, the child that would have developed asthma, but didn't. Public health is the disaster that didn't happen.
Public health in the final decades of the 20th century placed a heavy emphasis on individual responsibility for health and behavior modification. The newer definition from the CDC (Centers for Disease Control and Prevention) Foundation reflects a shift during the 21st century to a new era of "population health." In large part this shift was inspired by growing recognition of the social determinants of health and recognition of the importance of the social, cultural, and built environments. There was also growing recognition of many innovative strategies that were cropping up in cities and communities across the US. This included innovative ideas for improving the environment, safety, housing, transportation, schools and nutrition. Many of the most effective innovations were the result of collaboration across different sectors and disciplines, such as those called for by the 2002 report from the Institute of Medicine. Other factors that fostered this shift were growing disparities in health care, the threat of bioterrorism, the ever increasing cost of health care, and the need for community-based collaborations with those outside the sphere of traditional public health. Consequently, the shift to population health stresses not only the health of individuals, but the overall health of entire communities and populations.
Why are Quantitative Methods Important for My Career?
In 1988 The Institute of Medicine issued a report entitled "The Future of Public Health," which concluded that the US public health system needed refocusing, because there was a lack of clarity regarding its roles and responsibilities. The report introduced the concept of three core functions.
- Assessment: Assessing the needs of communities by collecting statistics and information related to the community's health needs. Assessment also means identifying the sources of health problems and the determinants of health and disease.
- Policy Development includes prioritizing public health needs, advocating for public health, building constituencies and coalitions, and pursing the enactment of policies and laws that promote health.
- Assurance means establishing and maintaining and infrastructure for public health and implementing programs to monitor the effectiveness of public health interventions. Assurance also requires effective communication of public health information to the general public.
In 1994 the CDC expanded the three core functions and identified ten essential services. Each essential service describes public health activities that should be undertaken in all communities, no matter how big or small.
It is likely that the ten essential functions of public health capture virtually all of the career goals of MPH students, but, in a sense, we all rely on the first two functions, monitoring and investigation, because we need the skills and tools that will enable us to identify health problems. We need to be able to keep track of the number of adverse health-related events in our populations, and we need to monitor those numbers over time in order to identify trends, the needs of the population, and the need for interventions. And we also need to keep track of health related events in order to estimate the need for future resources and be alerted to the emergence of new health problems. This requires that we have a means of measuring and tracking the frequency of health-related events in our populations. We also need to continually refine our understanding of the determinants of disease (and health), and this requires that we have methods for assessing exposures (risk factors) and health outcomes, and that we have methods for determining important associations between exposures and health outcomes. And, finally, we also need methods for determining the effectiveness of interventions.
This course provides an introduction to the quantitative and methodological approaches used in public health to ask and answer questions about health, and the course will primarily draw concepts and methods from three disciplines:
- Epidemiology: the science of understanding the causes and distribution of disease and health so that we may intervene to prevent disease and promote health
- Biostatistics: the application of statistical principles in medicine, public health or biology to draw meaningful conclusions from information or data
- Environmental health science: the science of assessing impacts of the environment (chemical, biological, genetic, physical, social) on human health
Population health science is the integrated quantitative discipline of public health that applies epidemiologic and biostatistical methods to information on health outcomes and exposures that could potentially affect health in order to answer public health questions.
For example,
- What are the important health outcomes being experienced in a population or in subgroups of a population?
- How are these outcomes distributed among groups of individuals? Are they increasing or decreasing in frequency?
- What exposures, behaviors, biological factors or social structures affect these health outcomes?
- How can we identify the determinants of a given health outcome?