Epidemiology: Scope, Uses, and Perspective

• Epidemiology is the distribution and determinant study of health events to control health issues in certain populations.

Scope of Epidemiology

• Epidemiology encompasses key health issues in communities.
• Communicable diseases are included.
• Chronic degenerative, metabolic, and neoplastic diseases are included.
• Nutritional deficiencies, as well as occupational health and injuries, are included.
• Mental, behavioral disorders, and demographic trends are included.

Uses of Epidemiology

• To pinpoint causative agents and populations at highest risk
• Concerned with describing the natural history of diseases including clinical and unapparent stages
• It is used to monitor the health of populations, and chart changes over time, place, and person.
• To determine which diseases are most important to public health
• To supply information necessary for program planning and disease prevention

Epidemiological Perspective Questions

• Who is affected, including age, sex, social class, ethnic group, occupation, heredity, and personal habits, which are person factors
• Where did it happen, in relation to geographical distribution, which are place factors
• When did it happen, in terms of months, season, or year, which are time factors
• What is the disease or condition, including its clinical manifestation and diagnosis?
• How did the disease occur, in relation to the interplay of the specific agent, vector, source of infection, susceptible groups, and other contributing factors
• Why did it occur, in terms of the reasons for the disease
• What action is now to be taken as a result of the information gained?

Disease Concept

• Health and disease are outcomes of the dynamic relationship between an agent, a host, and the environment.
• Equilibrium between factors indicates no disease.
• Disequilibrium indicates a disease due to changes in inherent characteristics of the agent, host, or environment.

Agents

• Agents are elements, substances, or forces whether animate or inanimate.
• The presence or absence of agents initiates a disease process.

Agent Classifications

• Biological agents like bacteria and viruses
• Nutritional agents like protein and vitamins
• Chemical agents like lead and solvents
• Physical agents like radiation and heat
• Mechanical agents like knives
• Social agents like poverty and work stress

Influences on Exposure Response

• Age, sex, family size, and marital status
• Religion, occupation, and ethnic or racial factors
• Habits and customs, plus inherent or nonspecific immunity influence exposure response.

Environment Factors

• Diet, nutrition, and sugar consumption contribute to decay causing bacteria leading to cavities.
• Poor oral hygiene causes plaque accumulation which encourages bacterial growth.
• Lower socioeconomic status is linked to limited access to dental care, preventive treatments, or hygiene education.
• Low fluoride in drinking water reduces tooth resistance to acids leading to dental caries.
• Tobacco-induced pollution is also a factor in periodontal disease and oral cancers.