Public health epidemiology is the scientific study of disease and other health-related issues and trends in populations of people. In reference to disease, this includes the causes, patterns of distribution, and measures for control. Other health-related issues studied may include the effectiveness of treatments and preventive measures, risk factors for health problems, and behaviors that improve health. The overall goal of the science of public health epidemiology is the prevention and control of disease as well as the promotion of positive influences on health.
Some examples of disease or illness studied in public health epidemiology include outbreaks of communicable illnesses such as influenza, norovirus and hepatitis, as well trends related to chronic illness such as asthma and diabetes. Health-related issues can also be studied, including the effectiveness of vaccination programs, mammogram usage, or exposure to chemicals and other environmental hazards. Positive behaviors that influence health, such as exercise or eating a balanced diet, are studied, as well as negative behaviors like smoking.
When studying these issues, the science of public health epidemiology investigates many factors. One of these would be the patterns of distribution. This refers to figuring out who is affected or involved. For example, what percentage of the total population, geographic location, and other shared characteristics exist. The demographics of the affected sample are also usually analyzed to determine if prevalence of the issue is related to gender, ethnicity, age, socioeconomic status or other factors. Time of occurrence is studied to see if there are patterns related to factors including seasons, days of the week, specific months, time of day, or other time-related issues.
Knowing more about the patterns of distribution can help in determining the cause, another area of study for public health epidemiology that is particularly useful. Both negative and positive health-related issues can be caused by a wide variety of factors, and understanding cause can help to determine the appropriate response. Some examples of causes of negative health issues like illness could be smoking, poor diet, and exposure to bacteria, viruses, chemicals, or other environmental hazards. Some examples of causes of positive health issues or behaviors include campaigns to encourage healthy lifestyles and environmental clean ups.
Once cause is determined, the next area for investigation in public health epidemiology would be establishing an appropriate response. This would include steps for the control of illness, including elimination of the cause if possible, vaccination, and disease prevention education efforts. In the case of outbreaks of communicable illness it could also include containment steps such as quarantines. When positive health issues are found such as an increase in healthy behaviors, the response could be to encourage the public to continue and increase the behaviors.