Epidemiology

Epidemiology is concerned with the distribution and determinants of health and diseases, morbidity, injuries, disability, and mortality in populations. Epidemiologic studies are applied to the control of health problems in populations.

1)All the inhabitants of a given country or area considered together;…”

2) population approach contrasts with clinical medicine’s concern with the individual

3) Epidemiology is sometimes called population medicine

The occurrence of diseases and other health outcomes varies in populations, with some subgroups of the populations more frequently affected than others.

Ex- biologic agents

Related to determinants are exposures- which pertain either to contact with a disease-causing factor or to the amount of the factor that impinges upon a group or individuals.

2) Expressed as types and measures of morbidity and mortality

illnesses due to a specific disease or health condition

• 2) use of statistics to: describe the occurrence of health outcomes and measure their association with exposures
• 3)Epidemiology is a quantitative discipline

The occurrence in a community or region of cases of an illness, specific health-related behavior, or other health-related events clearly in excess of normal expectancy.

• epidemic occurring worldwide, or over a very wide area, crossing international boundaries, and usually affecting a large number of people
• ―Ex.1918 influenza pandemic (Spanish Flu),AIDS pandemic,Obesity

type of prevention = during later stages of the disease progression of the disease

Epidemiology is an interdisciplinary science, meaning it uses information from many fields including

Epidemiology is an observational science- upon naturally occurring situations in order to study the occurrence of disease

refers to epidemiologic studies concerned with characterizing the amount and distribution of health and disease within a population

examines causal (etiologic) hypotheses regarding the association between exposures and health conditions

“Naturally occurring circumstances in which subsets of the population have different levels of exposure to a supposed causal factor in a situation resembling an actual experiment, where human subjects would be randomly allocated to groups.”

• Key events include:
• ─Bubonic plague epidemics
• ─Development of toxicology and biostatistics
• ─Development of smallpox vaccine
• ─1918 influenza pandemic
• ─Identification of smoking as a cause of cancer
• ─Eradication of smallpox

• Spanish Flu
• ─Killed 50 to 100 million persons globally
• ─(mortality rate of 2.5%) Estimates suggest that one-third of the world’s population became infected and developed clinically observable illness

• •Historical
• •Community health
• •Health services
• •Risk assessment
• •Disease causality

• 1) documents the patterns, types, and causes of morbidity and mortality over time.
• •Ex: Decline in infectious disease mortality

Describes a shift in the patterns of morbidity and mortality from causes related primarily to infectious and communicable diseases to causes associated with chronic, degenerative diseases

The epidemiologic transition coincides with the demographic transition, which is a shift from high birth rates and death rates found in agrarian societies to much lower birth and death rates in developed countries.

diagnose the health of the community and the condition of the people, to measure the true dimensions and distribution of ill-health in terms of incidence, prevalence, disability and mortality

• -To study the working of health services with a view to their improvement…”
• •Sample application: operational (operations) research

• 1) type of study of the placement of health services in a community and the optimum utilization of such services
• 2) Epidemiology helps to provide quantitative information regarding the availability and cost of healthcare services & what services needed in the community and what services are duplicated unnecessarily

Refers to a method of reducing healthcare costs by providing integrated care for chronic conditions. EX. Heart disease, Hypertension, Diabetes

estimate from the group experience what are the individual risks on average of disease, accident and defect, and the chances of avoiding them.”

The probability that an event will occur

is an exposure that is associated with a disease, morbidity, mortality, or adverse health outcome.

methodology used to provide quantitative measurements of risk to health

• 1) search for causes of health and disease by computing the experience of groups defined by their composition, inheritance and experience, their behavior and environments.”
• 2)One of the most important uses of epidemiology

• refers to “norms for conduct that distinguish between ... acceptable and unacceptable behavior.”
• ─Promotes the aims of research, such as knowledge, truth, and avoidance of error
• ─Promotes values that are essential to collaborative work, such as trust, accountability, mutual respect, and fairness
• ─Helps to ensure that researchers can be held accountable to the public ─Helps build public support for research
• ─Promotes a variety of other important moral and social values, such as social responsibility, human rights, animal welfare, compliance with the law, and health and safety

• Developed by the American College of Epidemiology (ACE)
• •The following are a few of these guidelines:
• ─Minimizing risks and protecting the welfare of research subjects
• ─Obtaining the informed consent of participants
• ─Submitting proposed studies for ethical review
• ─Maintaining public trust
• ─[Meeting] obligations to communities