The Impact of Epidemiology

Changing patterns of illness have been charted and followed by the field of epidemiology, a discipline closely relayed t to health psychology in its goals and interest. Epidemiology is the study of frequency, distribution, and causes of infectious and noninfectious disease in a population, based on an investigation of the physical and social environment. For example, epidemiologists not only study who has what kinds of cancer but are more prevalent than others in particular geographical areas.

In the context of epidemiologic statistics, we will see the frequent use of two important terms "morbidity" and "mortality". Morbidity refers to the number of cases of a disease that exist at some given point in time. Morbidity may be expressed as the number of new cases (incidence) or as the total number of existing cases (prevalence). Mortality refers to numbers of deaths due to particular causes.

In establishing the goals and concerns of health psychology and the health care endeavor more broadly, morbidity and mortality statistics are essential. We need to know the major causes of disease in this country, particularly those diseases that lead to early death, so as to reduce their occurrence. For example, knowing that accidents, especially automobile accidents, have historically been the major cause of death among children, adolescents, and young adults has led to the initiation of a variety of safety measures, including child safety restraint systems, mandatory seat belt laws, and airbags. Knowing that cardiac disease is he major cause of premature death ( that is, death that occurs prior to the expected age of death for an individual has led to a nationwide effort to reduce risk factors among those most vulnerable, including smoking reduction efforts, implementation of dietary changes, cholesterol reduction techniques, increased exercise, and weight loss.

But morbidity is as at least as important. What is the use of affecting causes of death if people remain ill but simply do not die. Increasingly, health psychology is concerned not only with biological outcomes but also with health-related quality of life and symptomatic complains. Indeed, some have argued that quality of life and expressions of symptoms should be more important targets for our interventions than mortality and other biological indicators. Consequently, health psychologists are becoming more involved in the effort to improve quality of life among those diagnosed with chronic illnesses so that individuals ay live out their remaining years are free from pain, disability, and lifestyle compromise as possible.