Epidemiology

Epidemiology

The study of the distribution and determinants of a disease frequency in human populations.

Epidemic/Outbreak

The occurrence of a disease in members of a defined population, more than the normal amount of cases in a population.

Pandemic

A disease that occurs throughout the population of a country, people, or world.

Epidemiologic Methods Purpose

To measure the commonness of health problems, find causes of diseases, decide on public health resource usage, and monitor prevention strategies.

History of Epidemiology

The study of how disease patterns have been analyzed and understood from ancient to modern times.

Distribution

Where, when, and who are affected by a disease.

Determinants of Disease

Factors necessary to test epidemiologic hypotheses regarding distribution and disease frequency.

Hypothesis

A statement derived from a theory predicting the relationship among variables.

Prevalence Rate

The number of preexisting cases of a condition in a population at a specific time, expressed per 100 of the population at risk.

Incidence Rate

The number of new cases of a disease occurring during a specific time divided by the population at risk.

Cohort Studies

Prospective studies that follow a group of people over time to study exposure and outcome relationships.

Case-Control Studies

Retrospective studies comparing participants who have a disorder with those who do not to determine differences in exposure.

Selection Bias

A problem in data collection where the sample does not represent the population being studied.

Bias

Errors in data collection that can influence the results of epidemiologic studies.

Causation

The relationship between a cause and its effect, determined through temporal sequence, consistency, and strength of association.

Random Variation

Chance differences between groups that can affect the results of a study.

Stratified Sample

A sampling method that involves dividing a population into subgroups and sampling from these strata.

Ecological Design

Study design utilizing existing data sources to examine relationships between outcomes and exposures at the population level.

Clinical Observations

Assessments made by healthcare professionals regarding the presence or absence of disease.

Proportion

A type of ratio where the numerator is part of the denominator, expressed as a percentage.

Cholera

A bacterial infection of the small intestine characterized by severe diarrhea and dehydration.