Epidemiology
Epidemiology is the study (or the science of the study) of the patterns, causes, and effects of health and disease conditions in defined populations. It is the cornerstone of public health, and informs policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive medicine. Epidemiologists help with study design, collection and statistical analysis of data, and interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies and, to a lesser extent, basic research in the biological sciences.
Major areas of epidemiological study include disease etiology, outbreak investigation, disease surveillance and screening, biomonitoring, and comparisons of treatment effects such as in clinical trials. Epidemiologists rely on other scientific disciplines like biology to better understand disease processes, statistics to make efficient use of the data and draw appropriate conclusions, social sciences to better understand proximate and distal causes, and engineering for exposure assessment.
Social Epidemiology
Social epidemiology is defined as "the branch of epidemiology that studies the social distribution and social determinants of health"; or in other words, "both specific features of, and pathways by which, societal conditions affect health" (Krieger, 2001). The roots of social epidemiology go back Emile Durkheim's work on suicide .
Émile Durkheim
Durkheim formally established the academic discipline and, with Karl Marx and Max Weber, is commonly cited as the principal architect of modern social science and father of sociology.
In Suicide (1897), Durkheim explores the differing suicide rates between Protestants and Catholics, arguing that stronger social control among Catholics results in lower suicide rates. According to Durkheim, Catholic society has normal levels of integration while Protestant society has low levels. Overall, Durkheim treated suicide as a social fact, explaining variations in its rate on a macro level, considering society-scale phenomena such as a lack of connections between people (group attachment) and a lack of regulations of behavior, rather than the feelings and motivations of individuals. Despite its limitations, Durkheim's work on suicide has influenced proponents of control theory, and is often mentioned as a classic sociological study. The book pioneered modern social research and served to distinguish social science from psychology and political philosophy.
Social epidemiology may focus on individual-level measures, or on emergent social properties that have no correlation at the individual level. Simultaneous analysis at both levels may even be warranted. Use of such multilevel models is also known as hierarchical and mixed effects models. Social epidemiology overlaps with fields in the social sciences, such as medical anthropology, medical sociology, and medical geography. However, these fields often use health and disease in order to explain specifically social phenomenon (such as the growth of lay health advocacy movements), while social epidemiologists generally use social concepts in order to explain patterns of health in the population.